In April 1542 a letter left Rome for the court of Charles V in Spain. On its first page the Italian stops in the middle of a line and digits begin:
\n*Figure 1. The opening of the cipher, f. 70r. Archivio Apostolico Vaticano\n(AAV), Segr. Stato, Spagna 1A, photograph supplied through\nDECODE record 92.\nDetail enlarged from the photograph.*
\nRead with the key recovered below, the first ten digits group like this:
\n73 4 57 4 9 03 5\n d o p o · l aDopo la, "after the". The 9 stands for nothing: it is a null. The\ndifficulty is deciding where each code ends. 73 is *d*, but 7 3 is also\ntwo letters, n m. Even with the key, a run of digits can be read more than\none way.
Two problems follow: finding the key without knowing where one code ends and the next begins, and then, once a key exists, telling the writer's words from a plausible guess.
\nThe sender was Cardinal Alessandro Farnese, grandson of Paul III and, at\ntwenty-one, head of the papal secretariat. The recipient was Giovanni Poggio,\nbishop of Tropea and nuncio, the Pope's ambassador, at the Emperor's\ncourt.<sup>1</sup> The letter opens in ordinary Italian: Poggio will have heard\nby word of mouth from Giovanni Ricci da Montepulciano about *la materia della\npace*, the peace between the Emperor and France, so Farnese will not repeat\nit. Montepulciano had returned from Spain in February with the Emperor's\nterms and had left Rome for Spain again in late March.2
\nMontepulciano's name is also on a cipher key. Aloys Meister's 1906 study of\npapal cryptography prints, among the old ciphers of the papal secretariat, a\nkey headed Cifra ultima con Mons. Poggio mandata per il Montepulciano: the\nlatest cipher with Poggio, sent by Montepulciano. Meister dates it 1538–42.3
\nThe letter fills eight pages on four leaves, 70r to 73v in the archive's\nnumbering: *r* for the front of a leaf, *v* for the back. Page 70r is\ncleartext for most of its length. Then the digits take over in the middle\nof a line and fill the whole of pages 70v to 72r. On 72v they surround a\ncleartext passage about church business and news from Ancona, "fresh and\nfrom a good source". The cipher ends on 73r, and the rest of that page is\nclear. Page 73v is clear and dated Da Roma alli X[?] di Aprile 1542: the\nday is a Roman numeral beginning with X whose remaining strokes lie under a\nflourish, still unread. What is in clear is the frame; the instructions are\nin cipher.4
\n*Figure 2. Ff. 70r and 70v. AAV, Segr. Stato, Spagna 1A, through\nDECODE record 92, public\npreviews. The change from prose to digits comes near the foot of 70r.\nThe cipher continues across the next page.*
\nLudwig Cardauns cited this volume in his 1912 collection of the nuncios'\nreports, but his selected correspondence does not include this letter.<sup>5</sup>\nIn July 2019 George Lasry set the text as Part 5 of the Vatican Challenge\non MysteryTwister, a site of cipher puzzles: key unknown, plaintext unknown,\nlanguage probably Italian.\nIn their study, published online in 2020, Lasry, Beáta Megyesi, and Nils\nKopal still listed the Spagna 1A material as unsolved. Their digit-frequency\nanalysis placed it in a separate cluster. They compared another part of\nthe collection, IA-1, with Meister's Poggio key, without success, and thought\nthis letter, IA-2, used a different key.<sup>6</sup> On 16 September 2026,\nthe challenge page still displayed zero solves.7
\nThe search began with a public transcription, now distributed with the\nDECODE record and the challenge. Its header credits EHum, dates the\ntranscription 9 January 2016, and records about six and a half hours' work\non the eight pages. The transcription contains 6,577 cipher digit positions:\n44 recorded as ?, unreadable, and 207 with a mark above them, mostly dots.\nThere is no consistent word division. The full ciphertext\nis reproduced as text, with its page and line breaks. The counts and searches\nbelow used this public transcription. I checked it against the larger\nphotographs later.8
In the public transcription, digit 7 makes up 17.5 percent of the text and\n1 only 3.1. A few pairs are far more common than chance: 80 occurs 349\ntimes, 57 317, 27 263, 03 258, 73 220. Doubled digits are nearly\nabsent: 00 six times, where independent digits would give about 117; 11\nthree times; 44 twice. And the digits alternate between two groups,\n4 5 6 8 and 0 1 2 7 9, with 3 belonging to neither: after 73, for\ninstance, the next digit is 6, 8, 4 or 5 in 93 percent of cases.9
*Figure 3. How often each digit follows each other digit in the public transcription.\nThe five pairs in bold turned out to be the codes for t, p, c, l, and d. The\npale diagonal is the avoidance of doubles. Author's computation from EHum's\n2016 transcription.*
\nThat looks like consonants and vowels taking turns. But it does not decide\nwhether 73 is one code or two frequent neighbors, and no fixed rule of\ncutting, such as pairs at even positions or certain digits always beginning\na pair, gave a consistent result.
The papal ciphers of the 1540s used several designs. In some, one digit\nstands for several letters and the reader chooses. In some, pairs spell\nsyllables. One 1545 key writes the vowels as pairs and the consonants as\nsingle digits.<sup>10</sup> I tried these designs with earlier versions\nof the search, without obtaining readable Italian.<sup>11</sup> The design\nthat fitted was a simple one also printed in Meister's collection: every\nletter has one code, of one or two digits, and the reader tells them apart\nby context.
\n*Figure 4. A key of that design: Meister no. 7, for Alessandro Vitelli,\ndated by Meister to 1546. Single digits for some letters, pairs for the rest,\none null, a few words. Aloys Meister, Die Geheimschrift (1906),\np. 179;\nGetty Research Institute copy, digitized by Internet Archive. Cropped from\nthe printed edition.*
\nI searched for the key and the code boundaries together. An outer search\nchanged the assignments of letters to codes. For each candidate key, an\ninner decoder searched for a good way to divide the digits and read them.\nThe outer search could then compare keys by how well their readings scored.12
\nTo judge those readings, I trained a character model that estimates the\nprobability of each letter from the four before it: a five-gram model. It\ntrained on about 4.9 million letters. Most came from Machiavelli,\nCastiglione, and Vasari on Wikisource. About 720,000 came from Italian-looking\nlines extracted from the OCR of Cardauns's Nuntiaturberichte aus Deutschland\nI.7, which includes correspondence of the Farnese secretariat from 1541–44.\nThat volume does not print this letter.<sup>13</sup> I lower-cased the text,\nstripped accents, folded *v* into *u*, deleted *h*, and collapsed doubled\nletters. These were guesses about the clerk's habits, and they turned out\nto match: the letter writes tute, esendo, facia; its key has one code\nfor *u* and *v* and none for *h*.
\nA letter sequence absent from the corpus still needed a chance. The model\nblended the counts for a four-letter context with estimates from shorter\ncontexts, down to individual letter frequencies. This smoothing let it score\nunfamiliar names and damaged words without ruling them out altogether.14
\nThe decoder walks the digits from left to right. Under the key eventually recovered, the opening has these two possible paths, among others:
\nDigits 7 3 4 5 7 4\nOne path 73 4 57 4 d o p o\nAnother 7 3 4 57 4 n m o p oThe first path consumes 73 at once and emits *d*; the second consumes 7\nand 3 separately and emits n m. Each emitted letter adds its base-10 log\nprobability to the path's score. The letters that follow can favor one path\nover the other, so the decoder keeps several partial readings alive.
Each partial reading is a state, which records the position in the digits,\nthe last four emitted symbols, and the score so far. If two paths reach the\nsame position with the same language-model context, their possible\ncontinuations are identical: only the better-scoring path needs to survive.\nAmong different contexts, the decoder keeps the eight best at each position.\nThis is a beam search. It is an approximation: a path discarded early cannot\nrecover when later letters would have made it convincing.
\nIn the successful searches, I set aside the digits with a dot or comma above\nthem and cut the text at those places and at unreadable digits. Each\nfragment began with a fresh language-model context. The key received the\nsum of its best surviving fragment scores, including penalties for nulls\nand digits it could not decode. The dotted codes would come back once the\nletters were known.15
\nThe outer search began with random assignments, favoring codes that occurred\nmore often. It could swap two assignments, move one to an unused code, or\nturn off an optional unit such as a null. It accepted any improvement. It\ncould also accept a worse key, with a chance that fell as the run went\non. This is simulated annealing. Accepting worse moves lets the search\nescape a key that beats its immediate neighbors but is still wrong. I\nrepeated the search from fresh random keys. Each repetition is a\nrestart.16
\nThe first search to produce recognizable Italian gave this opening, with underscores marking the null:
\ndopo_lapartitadelmontepinmcian_il_manonDopo la partita del Montepulciano, "after Montepulciano's departure". The\ncleartext on the same page mentions his departure. Further along were\nprepararsi contra … del turco, cento naui, ungaria, ridolfo gonzaga,\nforteza di luzara, mons. di granuela.
\nMuch of the rest was still garbage. This search had been allowed a pool of\noptional word codes, and it used them to explain away inconvenient digits.\nSearches that were allowed several nulls declared three frequent digits\nmeaningless. Allowing two codes per letter also gave high scores for worse\ntext. Yet four of the first search's six restarts had given the same codes\nto the same eighteen letters, the whole alphabet the clerk used. The letter\nassignments were stable even while the extra codes spoiled the reading.17
\nI tightened the search to one code per letter, at most one null, and no\nword codes. I also retrained the Italian model with word spaces removed.\nA model trained on del quale expects a boundary after the *l*, but the\ndecoder presents it with delquale. The unspaced model learns the letter\nsequences across those boundaries. With these changes, the search reached\nthe same letter key from two of three restarts. The third stopped at a worse\nkey.
Table 1. Settings for the tightened search.<sup>15</sup>
\n| Setting in the tightened search | Value |
|---|---|
| Candidate codes | Single digits and pairs occurring at least three times in the scored fragments |
| Breaks in the input | 203 above-dot/comma tokens and 44 unreadable tokens; one belongs to both groups |
| Input after those cuts | 219 scored fragments; 6,331 retained digits <sup>18</sup> |
| Beam width | Eight states per digit position |
| Proposal attempts per restart | 500,000 |
| Penalty per null | 1; emits no letter and preserves context |
| Penalty per undecodable digit | 4, when neither the single digit nor the available pair has a code |
The penalties discourage a key from improving its score by leaving text unread. Scores below divide the penalized total by the retained-digit count. Nearer zero is better. They rank the keys found under these settings, rather than measuring the probability that a reading is correct.
\n*Figure 5. The recovered key. The single digits 4, 5, 6, and 8 are the vowels\no, a, i, and e that the pairs table showed taking turns with the rest.\nAuthor's reconstruction.*
\nCould the same key be recovered without the opening name? I split the text after its third cipher page and solved each half on its own, from random assignments. Every restart recovered the same eighteen letters and the null.
\nI also enciphered known Italian with two invented keys of the same design: one synthetic cipher was clean; the other had digits substituted or marked unreadable. Finally, I shuffled the real ciphertext and searched that. These controls used the tightened search settings.
\nTable 2. Recovery and control runs.<sup>19</sup>
\n| Input | Result | Score per retained digit |
|---|---|---|
| Whole letter | Same eighteen letters and null in two of three restarts | −0.783; third restart −1.150 |
| First and second halves, solved separately | Same letters and null in all twelve restarts, six per half | −0.777 / −0.785 |
| Clean synthetic cipher | Letters and null recovered in all three restarts | −0.630 |
| Synthetic cipher with digit substitutions and 44 digits marked unreadable | Letters and null recovered in all three restarts | −0.692 |
| Shuffled real ciphertext | Best of two restarts | −1.351 |
The synthetic tests did not recover the word code for et, which the\nletter-only search could not express. Their Italian also later proved to\noverlap in part with the model's training text. All the controls share the\nItalian model and its habits, so the check I trust most is the split: either\nhalf of the letter alone yields the letter key and null.
\nLasry and his coauthors reported that, in their project, variable-length\nhomophonic keys (those allowing several codes for a letter) had required\nmatching plaintext or an already documented key. The simpler, monoalphabetic\nkey used here came out of the digits.20
\nWith the letters fixed, the decoded text around repeated dotted pairs\nrevealed their meanings. A 27 with the dot on its second digit, the 7,\nsat where Marchese has its che, and wherever the sense wanted che,\n"that". A 72 dotted on its second digit too sat where carichi,\n"burdens", has its chi; a 57, dotted the same way, where non si vede,\n"one does not see", has its non. With the dot on the first digit instead,\nthe same pairs gave qua, que and qui.
*Figure 6. The dot on the first digit gives qua, que, qui; on the second, che, chi,\nnon. Three more dotted pairs are titles: Sua Santità, Sua Maestà, Vostra\nSignoria, written here as the cleartext abbreviates them. Author's\nreconstruction.*
\nThe search alphabet had also included *q*, which the cipher does not need\nas a separate letter. In the tightened full-text run it occupied 81.\nThe decoded contexts gave that code the reading et, "and". The null 9\nis not a consistent word divider. It ends some words and not others, appears\ninside words (tu·te for tutte, the dot marking the null), and is used in\ncon, written 27 4 9 7. It can prevent misreadings: 8 9 0 reads\ne s, where 80 would be read as *t*.21
Recovering the key does not settle the text. The sequence 0 5 7 8 0 5\noccurs four times in the letter. Under the key it has two Italian readings.
*Figure 7. The digits 0 5 7 8 0 5 under the key: santa or spesa.\nAuthor's diagram.*
\nMy first reading, in three of the four places, was la santa [impresa], the\nholy enterprise, with a word supplied. The surrounding argument calls for *la\nspesa*, the expense, every time: the Pope will contribute what he can to the\nexpense; the ships may not be ready in the year the expense is for; he will\npay his share of the expense against the Turk.22
\nSome passages suggested errors in the digits themselves. In Montepulciano's\nname, the transcription gave 2, which the key reads as *r*, where the name\nneeded *u*. I wrote a second decoder to compare literal readings with readings\nthat required small changes to the transcription. The key, now including the\ndotted codes, stayed fixed.
The key search had cut the text at unreadable and dotted digits. This decoder\nworked through the cipher on each page, keeping the language context across\nunreadable places. It preserved the transcriber's qualifications:\n2? meant a doubtful 2, 1/2 offered two readings, and ? meant an\nunreadable digit. Dots, commas, and dashes above the digits were retained too.
At each position, the program compared the next digit or pair with the codes in the fixed key. An exact match cost nothing. Where nothing matched, it could propose a different digit or a changed above-mark. It could also drop a digit, supply the missing half of a pair, or insert a single-digit letter code. I assigned different costs to these operations so that filling a known hole was easier than contradicting a digit the transcriber had read without qualification.
\nTable 3. Edit costs in the fixed-key decoder.<sup>23</sup>
\n| Proposed operation | Cost in base-10 log units |
|---|---|
| Keep the digit, or the first offered alternative | 0 |
Fill an unreadable ? | 0.3 |
| Choose the second offered alternative | 0.5 |
| Substitute a listed look-alike for a digit marked uncertain | 1 |
| Substitute a listed look-alike for a digit not marked uncertain | 3 |
| Substitute a digit outside the list | 6 |
| Supply or ignore an above-dot | 3 |
| Ignore an above-comma / above-dash | 2 / 1 |
| Insert or drop a digit | 5 |
The look-alike list included such confusions as 1 with 2, 3 with 5\nor 7, and 0 with 8 or 9. These were hand-set costs, not measured\nerror probabilities.
The score combined the two kinds of evidence:
\nreading score = sum of letter log probabilities − sum of edit costsCode divisions and edits were searched together. A changed digit might join the next one into a pair, changing both the number of letters emitted and the context for the letters after them. As before, the decoder kept several partial readings alive and recorded the choices behind each one.
\nAt the disputed digit in Montepulciano, keeping 2 emits *r* without an\nedit cost. Choosing 1 emits *u* but subtracts three from the score. That\nchoice also changes the model's predictions for the following letters, until\nthe changed letter has passed out of its four-letter context. The gain in\nthe Italian score was enough for *u* to win. The edit list records:
Source Change Letter Context\n2 2>1 u elmontep [u] lcian ilThis repairs the middle of the name, but its final *o* is still absent.\nAnother proposal supplied the dot that turns 72, *b*, into 7̇2, que.\nThe result reads in quele di Ungaria, "in those [affairs] of Hungary", in\nplace of in ble di Ungaria.
The same scoring rule could damage a passage that already read correctly.\nOn 71r it proposed reading an 8 as the null 9 and regrouping the nearby\ndigits, turning a le sue sei galere, "his own six galleys", into\nal tuti galere. I refused that change. The model judged short letter\nsequences. It did not know how many ships the Pope had or follow the\nargument about paying for them. A gain large enough to pay for an edit\ncould still produce the wrong reading.
The edit list tied each proposal to its source digits and surrounding text. I could accept or reject a reading and locate the disputed digits in the photographs.
\nTable 4. Changes proposed by the decoder.<sup>23</sup>
\n| Type of proposed change | Value |
|---|---|
| Fills of unreadable digits | 44 |
| Other proposed operations, including choices of an offered alternative | 126 |
| Other operations divided by the public transcription's digit count | 1.9% |
The totals include rejected proposals. Whether an apparent error belonged to the transcriber, the clerk, or the reader still required checking against the page.
\nThe edited text, the edition from here on, uses\nsquare brackets for conjectural letters. A\ndigit-by-digit alignment behind it records what\nbrackets cannot show: ignored dots, dropped digits, digits read as the null.\nThe alignment makes departures visible; it does not make the readings true.24
\nTo test the conjectures, I gave the key to two readers, each a fresh run of the GPT-6 Astra language model, together with the digits of one page decoded literally under it: 72r for one and 71v for the other, the two pages with the most departures. Each was asked for a continuous reading and an account of every place where it left the literal decode. Each recovered its page's argument and many of the edition's words, and each caught something the edition had wrong.
\nOn 72r the edition had left a gap and supplied [che potrà] on no digits\nat all. The reader found that the twenty digits behind that gap read *verà\nla magior piena* exactly, "the greater flood will come". With the lost verb\nrecovered, the supplement was unnecessary. On 71v the edition had the Emperor\nknowing that the Pope's forces are small in themselves, S.M.tà s[a] che,\nat the cost of one 2 read as 5 and two digits read as nulls. The\nreader's o[l]tre che, "besides the fact that", needs one ignored dot and\none missing digit, and fits a sentence that goes on to say the forces are\nalso divided. Both were adopted. The readers were independent of the\nedition, not of the key or the transcription. Like the edition, they had\nnever seen the page.25
I checked the disputed readings against photographs of the manuscript.\nIn Montepulciano's name, the decoder wanted a *u* where the transcription\ngave 2, the code for *r*. On the page, the disputed digit is a single\nstroke with a foot: the clerk's 1, which gives *u*.
Transcription 57 2 03 27\nPage 57 1 03 27\nReading p u l c*Figure 8. F. 70r, second cipher line. AAV, Segr. Stato, Spagna 1A,\nthrough DECODE record 92; enlarged detail. The name was already a plausible\ncorrection from the Italian. The photograph shows why the digit was misread.*
\nThe clerk often joins one digit to the next. The top bar of a 7 runs into\nthe preceding digit. The foot of a 1 can make it look like a 2. In a small\npilot, I showed four short strips to three vision models. They made roughly\n12–18 percent digit errors, often on those same confusions. That pilot was\ntoo small, and its scoring too different, to establish a character-error-rate\ncomparison with the public transcription.26
I needed a way to compare a doubtful digit with the clerk's other examples.\nI wrote a program that first straightened each cipher line and removed the\nhandwriting's slant. It looked for cuts in the white gaps and the thin joins\nbetween digits, then fitted the transcription to those cuts. Each transcribed\ndigit became a provisional label on a small image. A 2 in the transcription\nmeant "this image is an example of a 2", even where that label would later\nprove wrong.
A seven-neighbor classifier compared each image with examples from other lines. It used their shapes and proportions to find the seven closest matches, then combined their labels to propose a digit. Leaving out the current line kept a digit from being compared with itself or a neighboring piece of the same joined stroke.
\n*Figure 9. The glyph transcribed as 2 in Montepulciano, followed by its seven nearest\nmatches from other lines. These are the straightened, normalized images used\nfor comparison. The labels come from the public transcription. Author's\nanalysis of AAV, Segr. Stato, Spagna 1A, ff. 70r–73r, photographs supplied\nthrough DECODE record 92.*
The classifier agreed with the transcription on 90.5 percent of the glyphs,\nand on 98.9 percent of the roughly two-thirds of glyphs it read most\nconfidently. Those figures measure agreement with the old labels. To find\ntranscription errors, I needed the disagreements.27
\nFor each suspect, a review sheet put the digit in its line of handwriting,\nbeside the seven matches and a reference sheet of the clerk's forms from\n0 to 9. I checked the ink and recorded the reading, the reason, and how\ncertain it was. I examined all 196 ranked suspects this way, together with\nevery line where the segmentation had found a different number of digits\nthan the transcription. Where the classifier doubted a\ndigit the edition had left alone, my reading mostly sided with the\ntranscriber: a smear could flatten a 3 into the shape of a 5, or the\nnext digit's stroke could give a 7 the base of a 2.28
Some errors were in the number of digits. On 71v the transcription repeated\nthe five digits that read anco, "also". The photograph has them once.
\nTranscription 5 7 2 7 4 5 7 2 7 4\nPage 5 7 2 7 4\nReading a n c o*Figure 10. F. 71v, fourth cipher line. AAV, Segr. Stato, Spagna 1A,\nthrough DECODE record 92; enlarged detail. The edition had already dropped\nthe second anco as a repetition by the clerk. The repetition was in the\ntranscription.*
\nThe check found five such doubled groups, totaling twenty-one digits not\non the page, as well as fourteen omitted digits and two swapped pairs. Some\nof the extra digits had supplied words for the edition: sendosi [c]osì firmat[o]\nbecame sendosi firmat[o], "having been agreed", with no così, "thus".29
\nOn 70v, a dot and two hooked 1s closed a gap in the account of the naval\nexpenses. The transcription had missed the dot over the 7 and read both\n1s as 2s.
Transcription 27 2 6 9 2 5\nPage 27̇ 1 6 9 1 5\nReading che u i · u a*Figure 11. F. 70v, third cipher line. AAV, Segr. Stato, Spagna 1A,\nthrough DECODE record 92; enlarged detail. With 1 standing for both u and v, this reads\nche vi va: the full phrase is della spesa che vi va dentro, "of the\nexpense that goes into it". The dot in the reading row marks the null 9.*
Other corrections confirmed letters the edition had supplied. In è s[t]ato\non 70r and aiu[t]o on 72r the transcription has 0 8 where the page has\n80, the code for *t*. The *s* of stato still has no digit behind it: the\npage has the null 9 there, so the edition now reads è [s]tato. Other\nbracketed letters, ris[p]osta and sol[d]o among them, stand on the page\nas the edition read them. Some letters the edition had supplied turn out to\nbe on the page: the *n* of Massimi[li]a[no] is a 7 the transcription\nread as 9; the *c* of ues[c]ou[o], vescovo, bishop, is a 2 the\ntranscription skipped, completing 27; the *i* of Dor[ia] is a 6\ndropped at a line end.
On 72r the edition had conte[n]ti with a supplied *n*. The page has a 7\nwhere the transcription has 4, and contenti is exact. On 70v the\nconjecture [ca]pitarà il bisogno is withdrawn: the transcription's 8 is a\n1, and the edition now reads [d]'ovunche più sarà il bisogno, "wherever the\nneed will be greater". The initial *d* remains conjectural. Other checks went\nthe other way. On 73r the edition had [ne]l qual luogo by changing a 6,\nbut the 6 is plain and the text reads il qual luogo. On 70r the 2 the\nedition read as 3 for contra [l]'armata has the clerk's usual 2 form:\nif *l* was meant, the clerk miswrote it.
One correction changed who had asked for a public announcement. Under the\narchive stamp on 72r, the corrected digits give la S.M.tà [h]a voluto,\n"His Majesty has wished", where the edition had read S.S.tà, His Holiness.\nThe Emperor had asked for the Hungarian subsidy to be offered publicly at\nSpeyer, in the Pope's name.
\nThe castle's name remains conjectural. Where the edition had supplied\n[Poviglio] from the Gonzaga genealogy, the corrected digits give\na pore in · pui ·, with the dots here marking nulls. The edition now reads\na porre in P[o]ui[glio], "to settle in Poviglio". The missing letters still\ncome from the proposed historical identification.30
\nI also checked the dots wherever the edition added or ignored one. In\nrisposta, the mark transcribed above a 7 was the top bar of the 5\nbefore it. Other apparent dots belonged to strokes from the line above. In\nMarchese, the dot was real but on the wrong digit of the pair: the clerk\nhad written qua where the name needs che.29
The corrections judged sure or probable went into a new transcription.\nUnresolved readings stayed open. I then aligned the edition against those\ncorrected digits.31
\n*Table 5. Source digits consumed by the edition's alignment. Both the\ntranscription and the edited reading changed after the page check.<sup>32</sup>*
\n| How the edition reads the digits | Before the page check | After |
|---|---|---|
| Digits in the transcription | 6,577 | 6,562 |
| Read exactly under the key, including nulls | 6,216 | 6,358 |
| Read with a recorded departure | 300 | 170 |
| Left in gaps | 61 | 34 |
Blots, the archive stamp, and smears along the page edges leave some digits and dots unread. I have not checked every glyph the classifier accepted, and substitutions between unlike digits still need another look. The day of the month also remains unread.
\nA contemporary copy in clear could help with the remaining readings. The\nArchivio Apostolico Vaticano searched the index to a register cited by\nCardauns, but found no entry for an April 1542 letter from Farnese to\nPoggio.33
\nThe summary below follows the proposed decipherment. Its quotations translate the edited Italian. Gaps and conjectures remain in the edition.
\nAfter Montepulciano's departure, the imperial ambassador in Rome, the\nMarqués de Aguilar, has been with the Pope and brought him Andrea Doria's\nadvice on arming against the Turkish fleet, and a request for help.34
\nThe Pope will hold back nothing within his means, at sea or in Hungary,\nwherever the need turns out to be greater. But nobody yet knows whether the\ngreater danger will come by land or by sea, and he will not decide where to\nspend, "so as not to fall into the error of spending in vain in one place\nthat needed it less, and then be unable to help the other." He leaves that\nto the Emperor's prudence.35
\nHe has two doubts about the plan to arm a hundred ships. He argues that a\nmixed fleet of galleys and sailing ships has never done well. And a hundred\nships would take so long to fit out that they would hardly serve this year,\nthe year the money is for. He will pay his share anyway, beyond his own six\ngalleys.36
\nThe soldiers on his ships must be his own. The Papal State is full of good\nsoldiers used to going to war. Unless he keeps them employed, no edict in\nthe world will stop them taking pay from whoever offers it, to the\ndisturbance of his own state and no advantage to the Emperor. He means, too,\nto stay neutral so that he can broker the peace, and to give nobody grounds\nto say he pays for anything but defense against the Turk.37
\nThen there are the other commitments. The Hungarian subsidy, which Charles V\nasked for at Lucca, was settled in Rome with the imperial minister Granvelle.\nAt the Emperor's request, the bishop of Modena, Giovanni Morone, has now\noffered it publicly, in the Pope's name, at the Diet of Speyer, the assembly\nof the German estates then in session. The enclosed extract from Modena's\nletter shows that those at the Diet are not content and ask for much more.\nAncona, Civitavecchia, the other ports, and the guard of Lombardy also need\nmoney. The Pope cannot yet say what more he will give on either\nside.38
\nFinally, Ridolfo Gonzaga, son of Gianfrancesco, is said to have taken a\ncommission from someone whose name is still unread. He gathered infantry at\nLuzzara, his brother Massimiliano's castle in Mantuan territory, then moved\nto his own castle in the territory of Parma and began to fortify it, either\nbecause the Marchese del Vasto, the governor of Milan, was preparing to\nremove him by force or for some design of his own. Whether this is mere\nrashness on Ridolfo's part or something larger is not yet clear. The\nPope's legate has orders to stop him, by force if necessary, and troops\nhave moved into Parma. Vederassi il successo: we shall see how it\ngoes.39
\nMorone's surviving reports independently confirm a public presentation of\npapal aid at Speyer on 23 March and complaints that the offer was too small.\nThey corroborate the decipherment's account, although the particular\nenclosed extract has not been identified.<sup>40</sup> The Pope and the Emperor\nhad met at Lucca in September 1541, two weeks after the Turks took\nBuda.41
\nThe Gonzaga genealogy also fits. Gianfrancesco's sons included Massimiliano,\nwho held Luzzara, and Rodolfo, spelled Ridolfo in the letter, associated\nwith Poviglio in the Parma territory. A published archival inventory\ndescribes a 1546 letter to Rodolfo as "signore di Poviglio". That supports\nthe proposed castle name without supplying its missing letters.30
\nThe peace Montepulciano was carrying did not come. Francis I declared war on\nCharles V in July 1542. By the end of that month Montepulciano was back in\nItaly. On 30 July the nuncio Girolamo Verallo reported Ferdinand's statement\nthat la pratica della pace era exclusa: the negotiation for peace was\nfinished.42
\nThis is a candidate reading. The key is stable: either half of the letter alone yields the same letters and null. The page check examined the disputed readings and the classifier's suspects, not every glyph.
\nNo other cryptanalyst has yet verified or challenged the solution. On\n15 September I sent the key and plaintext to MysteryTwister, whose team\nchecks Level X solutions by hand.7
\nThe notes identify the evidence for individual claims, including the article's own computations and proposed readings. References to printed books use their printed page numbers; manuscript references use folios. Cipher-line numbers count only lines containing cipher. English translations follow the cited Italian passages. The edition supplies word division, punctuation, and some spelling; its brackets and alignment record uncertain readings. Online catalog and challenge statuses were checked on 16 September 2026.
\n**Archivio Apostolico Vaticano (AAV), Segr. Stato, Spagna 1A,
ff. 70r–73v.** Letter identified here as Alessandro Farnese to Giovanni\nPoggio, Rome, April 1542; day unresolved.DECODE record 92 ,\nidentifierASV/i1025/SdS/Spain/IA/2 . Older references use ASV,\nArchivio Segreto Vaticano. The April date is the reading of this letter's\ndateline, rather than the wider date range assigned to the archival bundle.
EHum. Transcription ofASV_i1025_SdS_Spain_IA-2 , 9 January 2016.Public original ;complete transcription, including the transcriber's header ;ciphertext appendix and notation . This is the input to
the key search. Themanuscript-corrected transcription is a later research product, used for the edition's final alignment.
Borrelli, Luciano, ed. "Biblioteca trentina [parte seconda]."Studi trentini di scienze storiche , Sezione prima, 68, no. 2 (1989):
185–214.Digitized article .
Cardauns, Ludwig, ed.*Berichte vom Regensburger und Speierer
Reichstag 1541, 1542. Nuntiaturen Verallos und Poggios. Sendungen\nFarneses und Sfondratos 1541–1544* .*Nuntiaturberichte aus Deutschland\nnebst ergänzenden Aktenstücken* , I. Abteilung, vol. 7. Berlin, 1912.Digitized edition .\nCited below as Cardauns, with document number and printed page.
Fabbrici, Gabriele. "Geografia politica della pianura reggiana fra
XVI e XVII secolo. Note introduttive." In*Corti e diplomazia\nnell'Europa del Seicento: Correggio e Ottavio Bolognesi (1580–1646)* ,\nedited by Blythe Alice Raviola, 51–66. Mantova: Universitas Studiorum, 2014.Cited page 61 .
Gairdner, James, and R. H. Brodie, eds.*Letters and Papers,
Foreign and Domestic, of the Reign of Henry VIII* . Vol. XVII, 1542.\nLondon: Her Majesty's Stationery Office, 1900.British History Online, pp. 286–300 .
Gayangos, Pascual de, ed.Calendar of State Papers, Spain .
Vol. 6, part 2, 1542–1543. London: Her Majesty's Stationery Office, 1895.British History Online, pp. 1–13 .
Lämmer, Hugo, ed.*Monumenta Vaticana historiam ecclesiasticam
saeculi XVI illustrantia: ex tabulariis Sanctae Sedis apostolicae\nsecretis* . Freiburg im Breisgau: Herder, 1861.Digitized edition .
Lasry, George. "The Vatican Challenge — Part 5."MysteryTwister ,
7 July 2019.Challenge page ;challenge PDF .
Lasry, George, Beáta Megyesi, and Nils Kopal. "Deciphering papal
ciphers from the 16th to the 18th Century."Cryptologia 45, no. 6\n(2021): 479–540. First published online 23 June 2020.doi:10.1080/01611194.2020.1755915 .
Litta, Pompeo. "Gonzaga di Mantova," tavola XVI, "Marchesi di
Luzzara estinti nel 1794." InFamiglie celebri di Italia . Milano,\nsheet dated 1835.BnF/Gallica, view 26 .
Luzio, Alessandro.L'Archivio Gonzaga di Mantova . Vol. II,La corrispondenza familiare, amministrativa e diplomatica dei Gonzaga .
Verona: Officine grafiche A. Mondadori, 1922.Digitized edition .
Megyesi, Beáta, Nils Blomqvist, and Eva Pettersson. "The DECODE
Database: Collection of Historical Ciphers and Keys." In*Proceedings\nof the 2nd International Conference on Historical Cryptology* (2019),\n69–78.Open proceedings PDF .
Meister, Aloys.*Die Geheimschrift im Dienste der päpstlichen Kurie
von ihren Anfängen bis zum Ende des XVI. Jahrhunderts* . Paderborn:\nFerdinand Schöningh, 1906.Digitized edition .
Pastor, Ludwig von.*Geschichte der Päpste seit dem Ausgang des
Mittelalters* . Vol. V,Paul III. (1534–1549) . Freiburg im Breisgau:\nHerder, 1909.Digitized edition .\nDates and pages below refer to this 1909 edition.
Individual entries in the Dizionario Biografico degli Italiani are cited\nby their named authors, volumes, years, and online entry titles in the notes.\nTheir online text does not supply printed page breaks. Methodological\nreferences and the signed institutional history of Buda are likewise given\nin full at the relevant notes.
\nThe edition appendices contain the key tables,\nmachine-readable key,\nedited Italian text, and\ndigit-by-digit alignment. The\nautomatic reading preserves the decoder's proposals,\nincluding those rejected in the edition. The\ntranscription appendix includes the public and\ncorrected texts and the individual manuscript decisions. The\nresults supplement reports the search\nand control results, model details, and independent rereadings. The\nearlier alignment supplies the before-check\nfigures in table 5. These are the article's research outputs, not an\nindependently transmitted plaintext.
\nThe figure source register records source images, folios,\ncrop coordinates, transformations, and figure data. The public previews and the\nfull-resolution manuscript photographs are different files; the latter were\nsupplied through DECODE with restricted access and are not reproduced in full\nhere. The reproduced details and processed glyphs are identified individually\nin the register.
\nStefano Andretta, "FARNESE, Alessandro," *Dizionario Biografico\ndegli Italiani* (DBI) 45 (1995),online entry ,\nopening and the paragraph beginningIn questo periodo : born\n7 October 1520; appointed to the papal general secretaryship on\n1 January 1538, assisted by Marcello Cervini. Giampiero Brunelli,\n"POGGIO (Poggi), Giovanni," DBI 85 (2016),online entry ,\nrecords Poggio's appointment as bishop of Tropea on 4 October 1541\nand as nuncio to Charles V on 10 October. Both entries accessed\n16 September 2026.↩︎
\n200–201 :Sono otto giorni che m. Gio. Montepulciano tornò di Spagna .\nThis places the return about 10 February. The subsequent passage\nsays the terms will be proposed in France but does not identify\nRicci as the messenger. Gigliola Fragnito, "RICCI, Giovanni,"\nDBI 87 (2016),online entry (accessed 16 September 2026), gives the next departure as 28 March,\nas does Pastor,\nV,p. 471 n. 4 ,\nciting Serristori's report of 29 March (Florence, Med. 3264).\nSerristori's report itself has not been inspected here. Theedited cleartext on 70r printsalli XXV del [passato] , but the photograph has further\nnumeral strokes after the*V* ; thepublic transcription retains\nthem asXXV14^- . The numeral may readxxviij (28). The edition's\nshortenedXXV is not a secure reading and does not establish a\nconflict with the published chronology.↩︎
Meister (1906), section II, no. 2, pp. 176–177 .\nThe printed heading reads*[Zwischen 1538 und 1542.] Cifra ultima con\nMons. Poggio mandata per il Montepulciano* . The date is Meister's\neditorial dating. He gives the collection's manuscript source as\n"Rom, Bibl. Chigi M II 49 f. 85–148 und f. 168" on p. 176;\nthis is the source of the comparative keys, not of the letter.↩︎
\nAAV, Segr. Stato, Spagna 1A, ff. 70r–73v, DECODE 92. Compare the public transcription with the edition's70r ,72v , and73v . The phrase about the Ancona\nnews isfreschi et di bon loco . The edited cleartext contains\nsupplements and omissions; it is not a diplomatic transcription.↩︎
\nCardauns, pp. 437–441: the archival citation "Rom A. V. Spagna vol. 1 A f. 52–54 Or." is on p. 437 n. 2 .\nOnp. 439 he states that he selects passages concerning German affairs from\nthe fragmentarily surviving correspondence of 1542. This selection\ndoes not include the April letter. Its omission does not establish\nthat he attempted to decipher these leaves.↩︎
\nLasry, Megyesi, and Kopal (2021; online 2020), §5.5, pp. 501–502. Their comparison with Meister 176/2 concerns IA-1. On p. 502 they write: "The ciphertexts in the second part (IA-2) seem to belong to another key." Table 3, p. 496, places Segr. Stato Spagna-1A in\ncluster 16; that result concerns the collection, rather than this\nletter's digit counts alone.↩︎
\nLasry (2019), challenge PDF, pp. 4–5 ,\nfor the unknown key and plaintext and the tentative language\nidentification. Thelive challenge page gives the publication date as 7 July 2019 and displayed "0 solves"\nwhen checked on 16 September 2026. This is the site's recorded\nstatus. The author submitted the present result on 15 September;\nexternal verification was pending on 16 September.↩︎↩︎
\nEHum's transcription header records\neight times totaling 393 minutes (6 h 33 min). Megyesi, Blomqvist, and\nPettersson (2019), §4.1,p. 73 , explain\nthat the date field records submission and that working time excludes\nbreaks and quality checks. Thetranscription appendix records the counts: 113 cipher lines, 6,577\ndigit-position tokens, 44 unreadable tokens, and 207 above-marked\ntokens (178 dots, 25 commas, four dashes). DECODE's separate\nrecord-creation date, 18 October 2016, is not the transcription date.↩︎
\nAuthor's calculations from the public transcription. The counting rules and figure data specify overlapping windows, treatment of unreadable positions and\nalternative readings, and the joining of cipher lines and folios\nacross intervening cleartext. There are 6,492 readable two-position\nwindows. Digit percentages use all 6,577 positions as their\ndenominator. The expectation for00 is an independence comparison\nusing the observed frequency of0 , not a fitted model of the cipher.\nAfter the 220 occurrences of73 , the next token is6 ,8 ,4 ,\nor5 in 204 cases (92.7 percent); one next token is unreadable.↩︎
Meister (1906), no. 1, p. 176 ,\nfor single-digit polyphones; no. 2,p. 177 ,\nfor syllables such asca ce ci co =21 22 23 24 ; and no. 4,\npp. 177–178, the 1545 Mignanello key, for vowels11 13 15 17 19 and single-digit consonant codes, most with two possible readings.\nThese features can coexist in a key. No. 7, p. 179 (figure 4),\nsupplies the comparison with a mixed-length monoalphabetic design.↩︎
The exploratory-search summary describes the structure tests, unsuccessful searches, and\nMignanello-type vowel-pair test. These used several predecessor\nimplementations. Their negative results\ndescribe the searches made, not an exhaustive exclusion of those designs.↩︎
\nLasry, Megyesi, and Kopal, §6.10, pp. 522–524, already describe probabilistic variable-length decoding with Italian five-grams, logarithmic scores, and spelling normalization, explicitly for a cipher "for which the key is known" (p. 522). Here the outer search also changes the unknown key. ↩︎
\nThe corpus account identifies Machiavelli'sIl Principe ,Lettere ,*Discorsi sopra la\nprima Deca di Tito Livio* , andIstorie fiorentine ; Castiglione'sIl libro del Cortegiano ; and Vasari'sVite (1550).\nThe complete corpus contains 4,954,638 normalized letters, including\n729,754 from Cardauns; withholding 200 rows leaves 4,899,793 training\nletters, including 721,950 from Cardauns. A language heuristic selects\nItalian-looking lines, rather than identifying each letter's author.\nThe Wikisource metadata does not establish the underlying\nprint edition for every work. Thecorpus audit records metadata contamination, duplicate literary text, and sixteen\nheld-out rows also present in training; this is not a deduplicated\nor independently held-out corpus.↩︎
\nNormalization also folds j/y toi ,k toc ,w tou , andx tos .\nThelanguage model blends\neach context's observed distribution with shorter-context estimates,\nusing weighttotal/(total + distinct_next_symbols) ; the base is\nuniform. Unspaced training removes\nword spaces, retaining beginning/end-of-row sentinels.\nThe C solver uses a dense table of 3,200,000 float32 base-10 log\nprobabilities.↩︎
The search account specifies the beam\ndecoder, input preparation, and annealing settings. The tightened\nsearch used the unspaced model, no word units, 500,000 proposal attempts,\nthree restarts, and random seed 11. The candidate-code threshold is\napplied to the scored fragments. Invalid proposals are skipped but\nstill advance the cooling schedule. Above-comma tokens are treated as dotted for\nthese cuts; the four above-dashes do not trigger cuts.↩︎↩︎
\nS. Kirkpatrick, C. D. Gelatt Jr., and M. P. Vecchi, "Optimization by Simulated Annealing," Science 220, no. 4598 (1983): 671–680,\nespecially pp. 672–673,doi:10.1126/science.220.4598.671 (scan ).\nThis is the general method. Table 1 summarizes the cipher-specific\nsettings; thesearch account gives\nthe move probabilities and cooling schedule: swaps, 45%; moves to\nunused codes, 45%; deactivation of optional units, 10%. A worse key\nis accepted with probabilityexp(Δ/T) , whereΔ is the change\nin total score andT falls geometrically from 30 toward 0.5.↩︎
The search results include the first successful run, which produced the quoted opening\nand the common eighteen-letter key in restarts 0, 3, 4, and 5,\nalongside the three-null, homophone, and tightened searches.\nThese are exploratory runs with changing\nmodel inventories, rather than a controlled language-performance test.↩︎
\nThe retained-digit count includes 26 digits in fragments shorter than three, which the decoder does not score. The scored fragments contain 6,305 digits. The whole-letter scores divide by 6,331, matching the saved runs. ↩︎
\nThe control results report\nboth halves at seeds 11 and 23, the clean and noisy synthetic ciphers,\nand the shuffled ciphertext. The clean and noisy\ncases use different invented keys. Retained-digit denominators are\n2,591 and 3,740 for the halves, 6,165 and 6,119 for the synthetic\ncases, and 6,331 for the shuffle. Deterministic reruns reproduced\nthe recorded keys and scores. Training overlap is documented in\nthe corpus account cited above.↩︎
\nLasry, Megyesi, and Kopal, §5.3, p. 498: "In this project, the recovery of keys for variable-length homophones could only be achieved from matching plaintexts or by finding the key in the sources (e.g., Meister), based on characteristics identified via statistical analysis." The authors also report plaintext-assisted recovery of variable-length monoalphabetic examples F6 and P1 (pp. 499, 501). Their account does not establish a general limit on ciphertext-only recovery or priority for the present result. ↩︎
\nRecovered key, regular codes anddotted codes , with contextual\nexamples;machine-readable key .\nThese assignments are the article's reconstruction. Theunresolved marks include dotted signs whose meanings remain unknown. Theedition's alignment records the use of\neach assignment, including nulls, and the departures needed at\nindividual occurrences.↩︎
\nThe exact sequence occurs on f. 70v twice and f. 71r twice; line and token locators .\nSee theedition's reading note and thesaved automatic reading , which\npreserves the rejectedsanta readings. The choice betweensanta andspesa is contextual: both segmentations use the same key\nwithout changing a digit.↩︎
\nCosts for a digit and its mark add together; candidate-code matches costing more than 6.5 are rejected. Paths reaching the same digit position with the same four-letter context are merged, and the decoder keeps up to 64 contexts before advancing. It records the steps needed to trace the winning reading back to its digits. A literal null carries the context through unchanged at no cost; a title code resets the context without spelling its abbreviation into the language model. The automatic reading records the fixed-key\ndecoder's results under the edit costs in table 3, with source digits\nabove decoded units and changed units marked. Its folio 70r\nedit list includes the Montepulciano substitution; folio 71r\nincludes the rejected galley reading. Its final tally has 165 edited units\ncontaining 170 operations: 44 fills and 126 other operations;126/6577 = 1.916% . An operation count is not a measured\ntranscription-error rate, and rejected proposals remain in this output.↩︎↩︎
Editorial conventions andalignment notation .\nThe alignment procedure finds a least-cost alignment of an already\nsupplied edited text.\nBracketed supplied letters receive a reduced cost, and gaps can\nabsorb digits without cost. Its alignment therefore records how\nthe edition can account for the digits; it is not an independent\ntest of the edition's correctness.↩︎
\nThe rereading supplement includes\nthe 72r and 71v input packets and responses and describes the\nadopted corrections. Both successful\nreaders were fresh GPT-6 Astra runs. Their packets shared the\nlanguage-model-selected strict segmentation as well as the key and\ntranscription, omitted unreadable tokens and short fragments, and\nused the first listed alternative readings. They did not contain\nmanuscript images or the edition.\nThus their independence is limited to the subsequent reading task.↩︎
\nThe pilot account describes four strips totaling 55 reference digits and runs ofgrok-4.6 ,gpt-6-astra , andgemini-3.1-pro at#high .\nThe scoring allowed fractional alternatives and free crop-edge\nextras; its reference largely followed the public transcription.\nPrompts, responses, and the restricted-image crops\nare not included. This account supports a reported pilot,\nnot a reproducible comparative benchmark.↩︎
The glyph-classification account describes line leveling, slant removal, cuts, and token-to-ink alignment.\nNeighbor selection excludes references from the current line. The\nevaluation gives 90.549% agreement on 6,497 labeled glyphs and 98.885% on\n4,485 glyphs with vote share at least 0.9 (69.03% of the set).\nPCA and segmentation use the full dataset; line exclusion applies\nto the neighbor lookup. These are agreement rates against\nprovisional transcription labels. Figure 9'sprocessing record specifies\nthe features, distances, and source glyphs.↩︎
\nManuscript-check account ,individual decisions ,correction ledger , anddot decisions . All 196 classifier\nsuspects have entries in the decision ledger. Applying sure or\nprobable corrections at the original transcription's positions produces thecorrected transcription .↩︎
\nThe correction ledger identifies\neach change by folio, cipher line, and original token position.\nThe five doubled groups are 71v L04 p30–34, L05 p21–23,\nL09 p46–51, L20 p42–45, and 72r L07 p27–29: lengths5 + 3 + 6 + 4 + 3 = 21 . There are fourteen inserted digits and\n29 deletions overall, giving6577 − 29 + 14 = 6562 .\nThemanuscript-check account discusses the individual readings, including the two swapped pairs and\nthe Emperor's title on 72r; thedot ledger recordsrisposta at 70v L05 p26–27 andMarchese at 73r L01 p57–58.\nThe duplicated-digit count is the sum of the correction rows.↩︎↩︎
tavola XVI ,\nentriesGianfrancesco ,Massimiliano , andRodolfo , connects\nboth sons to Gianfrancesco and Laura Pallavicino. Their entries\ndiscuss the dispute over Luzzara and associate Rodolfo with thecastello di Poviglio nel parmigiano . The sheet reads*Stampata\nnel 1835* ; the BnF copy is NE-49 (A)-FOL, Gallica view 26 of 34.\nFabbrici (2014), p. 61, also identifies Massimiliano as\nGianfrancesco's son and successor at Luzzara. Borrelli (1989),p. 195, no. 592 ,\ndescribes a letter of Leoncino to "Rodolfo Gonzaga, signore di\nPoviglio," Mantua, 15 February 1546, with capitulations for the sale\nof Poviglio to Nicolò d'Arco: Guastalla, Biblioteca Maldottiana,\nFondo Davolio Marani, 12 n. 72. This is the published inventory's\ndescription; the underlying manuscript has not been inspected here.\nLuzio (1922),p. 262 ,\nplaces Poviglio among the Gonzaga possessions in the Parmense.\nThese sources support the contextual identification, not the absent\nletters inP[o]ui[glio] .↩︎↩︎
\nThe bracket check has a known omission: on 71r the *u* insua parte , "his share", is unbracketed although it needs1 and the corrected transcription offers3/7 . The alignment lists3/7>1 , but wrongly treats it as a choice between recorded alternatives.↩︎
The "before" column describes the pre-manuscript-check edition against the public transcription, preserved in the earlier alignment , final totals:5847 + 369 = 6216 exact tokens and nulls;260 + 18 + 22 = 300 tokens in edited units, read as nulls, or dropped.\nThe "after" column uses the revised edition and corrected digits,current alignment , final totals:5993 + 365 = 6358 exact tokens and nulls;154 + 10 + 6 = 170 tokens in the departure categories.\nBoth tokens of an edited pair enter that category even if only\none was altered. Supplied letters consume no source tokens and\ntherefore do not increase these counts.↩︎
Marco Grilli, Segretario della Prefettura, Archivio Apostolico Vaticano, email to the author, 16 September 2026; private correspondence. The report concerns index 1017 for Segr. Stato, Principi 14A, the register Cardauns cited as Principi 14. It does not report a folio-by-folio examination of the register and does not establish that no copy survives. The email itself is not reproduced here. ↩︎
\nAAV, Spagna 1A, ff. 70r–70v; edited decipherment, 70r and70v , fromDopo la partita tosecondo che V.S. scri[u]e per le sue . The letter says a copy of\nDoria's written summary accompanies it; that enclosure has not been\nidentified here.\nFor Aguilar's identification as Juan Fernández Manrique de Lara y\nPimentel and his Roman embassy, see Cascella Alcaraz (2025), pp. 63–64.\nFor Andrea Doria's imperial naval command, Edoardo Grendi,\n"DORIA, Andrea," DBI 41 (1992),online entry ,\nthe 1528asiento paragraph (accessed 16 September 2026).↩︎
\nAAV, Spagna 1A, ff. 70v–71r; edition, 70v ,*acciò che non si cadesse in questo errore di spender in vano in un\nluogo che manco lo ricercasse, et non poter di poi supplir a l'altro\ndove fusse maggior il pericolo* . The English quotation translates\nthis passage.↩︎
\nAAV, Spagna 1A, f. 71r; edition ,armar le cento navi throughsua parte che [l]i toccherà .\nThe judgment about mixed fleets is the Pope's argument as reported\nin the letter.Navi is rendered as sailing ships in contrast togalere ; the six galleys are explicit in the decipherment.↩︎
\nAAV, Spagna 1A, ff. 71r–71v; edition, 71r ,Ma quanto a le fanterie , continuing on71v toper la difesa dal Turco .↩︎
\nAAV, Spagna 1A, ff. 71v–72r; edition, 71v ,tra le quali è lo aiuto di Ungaria , continuing on72r . The corrected readingla S.M.tà [h]a voluto attributes the request for a public offer\nto the Emperor. The enclosedcapitulo has not been identified as a\nseparate witness. Speyer is named in the cleartext on73r ,della [dieta] di Spira .\nMassimo Firpo, "MORONE, Giovanni," DBI 77 (2012),online entry (accessed 16 September 2026), confirms his bishopric and attendance\nat Speyer in 1542. Granvelle here is Nicolas Perrenot: Gayangos\n(1895), no. 2, pp. 2–7, especiallyp. 3 and its identifying note ,\nand no. 6, pp. 10–11, addressed to him as the Emperor'sGarde-sceaux .↩︎
\nAAV, Spagna 1A, ff. 72v–73r; edition, 72v ,Il Signor Ridolfo Go[n]zaga , continuing on73r toVederassi il successo .\nThe unidentified employer and conjectural castle name remain open;\nthis summary does not independently establish the troop movements.\nFor the identification of the Marchese del Vasto as Alfonso d'Avalos,\ngovernor of Milan from 1538, see Gaspare De Caro, "AVALOS, Alfonso d',\nmarchese del Vasto," DBI 4 (1962),online entry ,\nthe paragraph beginningAlla morte del Caracciolo (accessed\n16 September 2026).↩︎
\np. 420 :Alli XXIII. hebbi audientia publica and*esposi la mente di N. S.\nsopra l'aiuto contra il Turcho* . The response acknowledges his\nproposal in the Pope's name. Lämmer's heading dates the report\n28 March; Cardauns, p. 127 n. 1, refers to it as 29 March. The\npresentation's date, 23 March, is explicit in the text.\nMorone's report of 30 March, Cardauns, no. 63, pp. 127–130, at128, lines 6–17 ,\nsays*Quanto al aiuto contra il Turcho tutti si aggravano parendoli\npoco* ; the majority wanted 5,000 infantry without conditions and\n2,000 cavalry. These passages establish the presentation and\ndissatisfaction, not Charles V's personal instruction or the\nidentity of the letter's enclosure. Earlier discussions with the\nEmperor at Lucca and then Granvelle are attested in Farnese to\nVerallo, 7/10 January 1542, Cardauns, no. 93, pp. 192–195, at193 .\nThat passage does not independently establish the precise Roman\nsettlement described in the decipherment.↩︎
\nPastor, V (1909), pp. 456–458, especially 457 :\nCharles V arrived and met Paul III on 12 September 1541; extended\ndiscussions began the next day. Károly Magyar, "Buda in the Turkish\nEra,"The Castle of Buda , signed institutional account credited\nto the Budapest History Museum and HAS Research Centre for the\nHumanities,part 1, final paragraph (accessed 16 September 2026), dates the Ottoman occupation to\n29 August. The interval to their first meeting was fourteen days.↩︎
\nGairdner and Brodie (1900), p. 287, no. 492, "The War" ,\ncalendars Francis I's proclamation against the Emperor, dated\nLigny, 12 July 1542, from a copy at Simancas. For Ricci's return to\nRome on 22 July, see Fragnito, "Ricci," and Pastor, V,p. 472 .\nThe quotation is in Verallo to Farnese, Nuremberg, 29/30 July,\nCardauns, no. 112, pp. 229–233, at231, the 30 July continuation :la Mtà del re mi ha communicato that Montepulciano had returned\nandla pratica della pace era exclusa . Verallo is reporting\nFerdinand's account. Ricci's mission had failed; papal mediation\ncontinued, with new peace legates appointed on 7 August (Pastor,\np. 472).↩︎
","headings":[{"level":1,"text":"The Farnese letter","id":"the-farnese-letter"},{"level":2,"text":"The letter","id":"the-letter"},{"level":2,"text":"What the counts show","id":"what-the-counts-show"},{"level":2,"text":"The search","id":"the-search"},{"level":3,"text":"Reading a candidate key","id":"reading-a-candidate-key"},{"level":3,"text":"Changing the key","id":"changing-the-key"},{"level":3,"text":"Checking the key","id":"checking-the-key"},{"level":2,"text":"Dots and the null","id":"dots-and-the-null"},{"level":2,"text":"What the digits say and what the model wants","id":"what-the-digits-say-and-what-the-model-wants"},{"level":3,"text":"Reading through errors","id":"reading-through-errors"},{"level":2,"text":"The edition","id":"the-edition"},{"level":2,"text":"The page","id":"the-page"},{"level":2,"text":"What Farnese put in cipher","id":"what-farnese-put-in-cipher"},{"level":2,"text":"Status of the decipherment","id":"status-of-the-decipherment"},{"level":2,"text":"Sources and research materials","id":"sources-and-research-materials"},{"level":3,"text":"Manuscript and transcription","id":"manuscript-and-transcription"},{"level":3,"text":"Published sources","id":"published-sources"},{"level":3,"text":"Research data and illustrations","id":"research-data-and-illustrations"},{"level":3,"text":"Notes","id":"notes"}]}}![p. 471 n. 4](\"https://archive.org/download/geschichtederp05past/page/n518.jpg\"){kind=link}
![457](\"https://archive.org/download/geschichtederp05past/page/n504.jpg\"){kind=link}
![p. 472](\"https://archive.org/download/geschichtederp05past/page/n519.jpg\"){kind=link}