01 The letter
| Shelfmark | BnF Français 3142 · Du Bellay, ff65–66 |
|---|---|
| Sender | Jean, cardinal Du Bellay |
| Recipient | The Constable |
| Date | Undated |
| Language | French |
| Report status | 4/4 pages transcribed; 1/4 pages deciphered; 3 more in part |
| Ciphertext | 851 elements,547 identified (64.3%) |
02 The key
43 symbols The key was recovered from the ciphertext alone.
03 The decipherment
f66r, cipher lines 10–12
à ses freres et aux gens de Burgos les raisons qui luy poisent sur le cueur il les veult payer de bourdes [?] devant eulx pource [?]
Translation. To his brothers and the people of Burgos, the reasons that weigh on his heart; he wishes to fob them off with tales [?] before them because [?].
04 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 A. Image checked: https://gallica.bnf.fr/ark:/12148/btv1b9060320r/f68.item
- Folio matches the report: yes; cipher present: yes
- What we checked: f65r: mixed clear/cipher, clear names "monsr le connestable", "pape Julio"; cipher sign set (#, /, ψ, ∞-like, ≡) matches his 43-sign table; f66r excerpt lines not decoded at this resolution
- Verdict: partly confirmed (method key recovered from ciphertext-only, extent partial). The check is a sample, not a re-solution.
- Notes: Only 64.3% identified, 1/4 pages fully deciphered. Clear text names Pope Julius (III), so the "undated" letter is 1550-55, consistent with slug 1555.
05 Notes and corrections
Folder renamed from the report's slug dubellay1555b (ff. 65–66). The clear text names Pope Julius (III), which dates the letter 1550–55.
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. 34; his other items are listed on his contributor card.
- The working folder:
targets/dubellay65/(his entry as extracted from the report, our spot-check,profile.json).