Piu sobria sara V.Ecc. nel scriuere in Italia, masime in modo che posi risapersi tanto. Sara meglio l’auuisare…

BnF Français 4696 · contributed by George Lasry · Italian

Not established to Not established, 1589?

Intercepted letters disclose political loyalties in France. The Pope knows the cipher; the writer urges changing it, writing more cautiously to Italy, and sending the Duke of Mantua news of France by a secure route. Deciphered by George Lasry, working with ChatGPT Astra 6 and Anthropic Opus 5.5, in his BnF cipher research of October 2026: 1,744 elements, 1,692 identified; 1 obscured group of unknown length. His full report (24 October 2026) is reproduced below; the whole text measures 99.6% of words read as sense and the deciphered passages 99.1%, but the report itself calls two of the three pages deciphered only in part (2 codes unidentified, 1 group obscured): partial.

George Lasry · posted · updated

Method: key recovered based on adjacent plaintext · Extent: partial (99% of the cipher)

Contributed by George Lasry (solution)

George Lasry’s decipherment

George Lasry’s report on this item, as he sent it on 24 October 2026 (PDF), in its own order and wording. The decipherment, the translation and the reconstruction of the key are his, made with ChatGPT Astra 6 and Anthropic Opus 5.5. This project’s own checks follow under Verification.

Français 4696 — numerical cipher, ff54r–55r

Contents: Intercepted letters disclose political loyalties in France. The Pope knows the cipher; the writer urges changing it, writing more cautiously to Italy, and sending the Duke of Mantua news of France by a secure route.

3/3 pages transcribed; 1/3 pages deciphered; 2 more in part

Ciphertext-only:
No
Sender:
Not established
Recipient:
Not established
Year:
1589?
Key:
70 codes: 49 letter signs, 19 in nomenclature, 2 unidentified
Ciphertext:
1,744 elements, 1,692 identified; 1 obscured group of unknown length
Interlinear plaintext:
Historical interlinear plaintext on ff54r–55r.
The reconstructed key, from George Lasry’s report.
The reconstructed key, from George Lasry’s report. Image: key reconstructed by George Lasry (report, 24 October 2026); sign images: Bibliothèque nationale de France, Français 4696, via Gallica.

Excerpt and Translation

f55r, full cipher lines 1–6

The manuscript lines of the excerpt (f55r, full cipher lines 1–6).
The manuscript lines of the excerpt (f55r, full cipher lines 1–6). Image: Bibliothèque nationale de France, Français 4696, f55r, via Gallica; crop from George Lasry’s report.

Excerpt

Piu sobria sara V.Ecc. nel scriuere in Italia, masime in modo che posi risapersi tanto. Sara meglio l’auuisare il serenisimo signor duca di Mantua frequentemente et per uia sicura de i sucesi di Francia. Sara sopra modo grato a S.A. a quale et a V.Ecc. tornara molto a conto.

Translation

The more restrained Your Excellency is in writing to Italy, especially in a way that could become known, the better. Informing the Most Serene Duke of Mantua frequently, and by a secure route, of events in France will be exceedingly welcome to His Highness and will greatly benefit both him and Your Excellency.

Readable text

The full text, folio by folio, as in the report. Bold marks the passages deciphered from the cipher; the rest is the clear text of the letter. Question marks are the report’s: [?] or a bare ? for a sign or group left unread, a ? after a word for a doubtful reading.

Français 4696 — ff54r–55r

f54r

Nostro S.re staua alterato con il S. D. di Neuers per le lettere intercette di S. Ecc., nelle quali tassaua le attioni di sua santità et diceua male del Re di Spagna. Se tutta uia per amor di S.A. uole accordare questi disgusti et si contentaua di instantia de la stessa S.A. di scriuer al legato che facese instantia efficacissima a nome di sua santità con quelli de la lega perché restituiscono a S.E. la figlia et terre occupateli. Et che credeua che ? ubidito senza venir a minacie di scomuniche, che sua santità riceuerà in gratia S.E. scordandosi il passato, sempre che desista di scriuer lettere a chi si sia quali contenghino maledicenze di sua santità et del Re di Spagna, come ha fatto per tutto il mese di ottobre.

Dicendo molto bene che signori uenetiani affermano che hano aiutato il re morto col prestito di trecento mila scudi et hora ne hano dato ? 200 mila, dolendosi di sua santità perché non lo faccia generale suoi in Francia, affermando di uoler seguitare la parte di Navarra come fano tanti altri catolici francesi. Afferma sua santità hauer le lettere

f54v

in mano di S.E., continenti le sodette cose. Aggiunge sua santità che uolendo eser generale di santa chiesa non doueua dir male di sua santità et che hano nociuto a signori uenetiani con publicare li aiuti dati al Re di Navarra et che non gioua punto ale cose sue col dir tanto male del Re di Spagna. Et che se bene alcune de le sodette lettere sono scritte in cifra, nondimeno sono intese, sapendosi la cifra, la quale come prudente dourebbe mutare et guardarsi da scriuere cose così fatte. Si è conosciuto che le lettere sono intercette in Lione et che sua santità gode di ciò per scoprire le inclinationi di ognuno in Francia.

Sentirebbe sua santità molto dispiacere che V.Ecc. intrasse al parlamento di Navarra et apertamente seguise la parte di esso Navarra. Dice sua santità che per uia di Lione sono state mandate al Re di Spagna copia dele lettere di S.Ecc. che contengono le male dicenze di S. Maestà. Si intende che il Grim? detto Zin? che serue V.E. in Genoua publica li affari di V.Ecc. con poca prudentia et pregiuditio del seruitio di lei, la quale acciò douerà pore quel rimedio et prouisione che più le parerà conueniente. Quanto

f55r

Piu sobria sara V.Ecc. nel scriuere in Italia, masime in modo che posi risapersi tanto. Sara meglio l’auuisare il serenisimo signor duca di Mantua frequentemente et per uia sicura de i sucesi di Francia. Sara sopra modo grato a S.A. a quale et a V.Ecc. tornara molto a conto. Si spedisca il p[rese]nte corr[iero] in diligenza a fine che le mie capitino presto et sicuramente.

At a glanceKey from adjacent plaintext · partial (99% of the cipher)

The letter
Sender, recipient and date (1589?) not established; an Italian letter advising a correspondent to write less openly to Italy and to inform the Duke of Mantua of events in France.
Where
Bibliothèque nationale de France, Français 4696, f55r.
The cipher
70 codes: 49 letter signs, 19 nomenclature and 2 unidentified.
How it was read
Lasry recovered the key from the contemporary interlinear plaintext on ff54r–55r. The spot-check matched his excerpt against the interlinear; digits were not decoded again.
What it says
Informing the Duke of Mantua frequently and by a secure route will please him and benefit the writer’s correspondent.
Still open
Only one of three pages is fully deciphered, though 97% of elements are identified.
Credit
George Lasry, with ChatGPT Astra 6 and Anthropic Opus 5.5 (BnF cipher research, 10 October 2026). This project only spot-checked one sample against the image.

01 Verification

Spot-check against the manuscript

This result is George Lasry’s. This project did not re-solve the cipher: it checked one sample against the Gallica image and recorded what it found.

02 Other contributions

Interlinear plaintext
Historical interlinear plaintext on ff54r–55r.

Full texts

The transcription and the decryption of every document on this page, so that the reading can be used and checked. Short files are shown here; all are in the repository.

George Lasry's decipherment (report PDF, 24 Oct 2026) read in part

Intercepted letters disclose political loyalties in France. The Pope knows the cipher; the writer urges changing it, writing more cautiously to Italy, and sending the Duke of Mantua news of France by a secure route. Sender and recipient not established, 1589?, as given in George Lasry's report.

Builds coherent sentences, but under the read bar of 95% of words read as sense (100% here); the holes are marked in the reading.

Decryption: in full above, in George Lasry’s decipherment (readable.md)

Reading: in full above, in George Lasry’s decipherment (readable.md)

Translation: in full above, in George Lasry’s decipherment (translation_excerpt.md)

03 Sources