De Villardeau (BnF Clairambault 531)

01 The letter

Shelfmark	BnF Clairambault 531 · testament and Holstein marriage
Sender	De Villardeau (Holstein letter, signed on p125); testament memorandum anonymous
Recipient	Unestablished
Date	Undated selected sheets; Russian-correspondence dossier, 1725–1730
Language	French
Report status	6/6 pages transcribed; 5/5 cipher pages deciphered
Ciphertext	1,248 elements, 1,237 identified (99.1%)

02 The key

214 code assignments: 44 letter codes, 170 in nomenclature; 43 corresponding offset pairs

George Lasry’s reconstructed key table — George Lasry’s reconstruction of the key, as drawn in his report (p. 124). Image: George Lasry, BnF cipher research (10 Oct 2026); manuscript: Bibliothèque nationale de France, Clairambault 531, Gallica btv1b9000658k view 73.

03 The decipherment

Manuscript lines with the cipher, from George Lasry’s report — The manuscript lines of the excerpt (p124), from the report, p. 125. Image: George Lasry, BnF cipher research (10 Oct 2026); manuscript: Bibliothèque nationale de France, Clairambault 531, Gallica btv1b9000658k view 73.

p124

Veue d’egayer ma lettre, mais parce que je sçais qu’il est important qu’un ministre sache si un prince qui aspire à une couronne est en estat d’avoir des successeurs.

Translation. The purpose is not to enliven my letter, but because I know it is important for a minister to know whether a prince who aspires to a crown is capable of having successors.

04 Plaintext and other sources

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

Interlinear plaintext: Historical interlinear plaintext on pp77, 79, 81 and 123–124.

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/btv1b9000658k/f73/full/1400,/0/default.jpg
Folio matches the report: yes; cipher present: yes
What we checked: p124 (canvas 73): clear "Veue degayer ma lettre mais parceque je scais" then interlinear over 3 code rows "quil est important quun ministre sache si un prince qui aspire a une couronne est en estat davoir des successeurs" = his excerpt; signed De Villardeau on p125
Verdict: confirmed (method key recovered based on adjacent plaintext, extent complete). The check is a sample, not a re-solution.
Notes: Mentions Campredon ill at St Petersburg, so 1725-26 (Holstein wedding 1725). Interlinear present on the cipher pages; 99.1% identified.

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. 124; his other items are listed on his contributor card.
image checked in the spot-check
The working folder: targets/villardeau/ (his entry as extracted from the report, our spot-check, profile.json).