Vicomte de Turenne to The Grand Master, 1 June 1528 (BnF Français 2999)

01 The letter

Shelfmark	BnF Français 2999 · Turenne, ff13r–13v
Sender	Vicomte de Turenne
Recipient	The Grand Master
Date	1 June 1528
Language	French
Report status	2/2 pages transcribed; 1/2 pages deciphered; 1 more in part
Ciphertext	785 elements, 775 identified (98.7%)

02 The key

46 symbols: 31 letter signs, 4 in nomenclature, 6 nulls, 5 unidentified; 2 further sign readings uncertain.

George Lasry’s reconstructed key table — George Lasry’s reconstruction of the key, as drawn in his report (p. 131). Image: George Lasry, BnF cipher research (10 Oct 2026); manuscript: Bibliothèque nationale de France, Français 2999, Gallica btv1b90599722 view 13.

03 The decipherment

Manuscript lines with the cipher, from George Lasry’s report — The manuscript lines of the excerpt (f13r, three complete consecutive rows2–4), from the report, p. 131. Image: George Lasry, BnF cipher research (10 Oct 2026); manuscript: Bibliothèque nationale de France, Français 2999, Gallica btv1b90599722 view 13.

f13r, three complete consecutive rows2–4

ne qu’il face, ie pance que le vouloir qu’il a de se vanger des Florentins et du duc de Ferrare lui feroist faire beaucoup de choses qui par advanture

Translation. nor whatever he does, I think that his wish to take revenge on the Florentines and the Duke of Ferrara would make him do many things that perhaps …

04 Plaintext and other sources

Where a decipherment or clear copy already existed, as George Lasry gives it:

Interlinear plaintext: Interlinear plaintext on the same selected pages, f13r–v.

05 Our check

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.

Batch B. Image checked: https://openapi.bnf.fr/iiif/image/v3/ark:/12148/btv1b90599722/f13/full/1600,/0/default.jpg
Folio matches the report: yes; cipher present: yes
What we checked: f13r cipher rows 2-4: contemporary interlinear "...pance que le vouloir quil a de se vanger des Florentins et du duc de Ferrare luy feroist beaucoup de choses qui par advanture" = his excerpt; sign-level decode not done
Verdict: confirmed (method key recovered based on adjacent plaintext, extent partial). The check is a sample, not a re-solution.
Notes: f13v only in part (1/2 pages fully deciphered) though 98.7% of elements identified. Docket "1528 Italie". Turenne (Francois de La Tour) in Rome 1528 fits.

06 Sources

George Lasry, with ChatGPT Astra 6 and Anthropic Opus 5.5, BnF cipher research, 10 October 2026 (sent to Daniel Bourdeau on 13 October 2026 for publication here), p. 131; his other items are listed on his contributor card.
image checked in the spot-check
The working folder: targets/turenne1528/ (his entry as extracted from the report, our spot-check, profile.json).