01 The letter
| Shelfmark | BnF Français 3318 |
|---|---|
| Sender | Charles IX |
| Recipient | Jean de Vulcob |
| Date | 7 March 1573 |
| Language | French |
| Report status | Transcribed; Deciphered |
| Ciphertext | 754 elements, 746 identified; 4 groups with unresolved boundaries and 19 null-marked groups not included in these counts |
02 The key
43 identified symbols, 39 letter signs, 4 in nomenclature
- Key elsewhere
- Comparison key in a different volume: Colbert 398; 14 shared letter forms.
03 The decipherment
f32r, complete cipher lines 13–15
…election l'archiduc Erneste, sont semblables a ceu? que le sieur de Tanneberg a tenuz a la court de mon frere le duc de Lorraine sur ce fait et pourroit bien estre ?
Translation. …election, Archduke Ernest, resemble what the sieur de Tanneberg has said on this matter at the court of my brother, the Duke of Lorraine, and it could well be ?.
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 page, f32r.
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 A. Image checked: https://gallica.bnf.fr/ark:/12148/btv1b9060207j/f33.item
- Folio matches the report: yes; cipher present: yes
- What we checked: f32r "Monsr de Vulcob", cipher block with contemporary interlinear; the interlinear over the excerpt lines reads "election larchiduc ernestes ont semblables a ceux que ...", matching his "election l archiduc Erneste, sont semblables a ceu? que"; symbols not re-decoded independently
- Verdict: confirmed (method key recovered based on adjacent plaintext, extent complete). The check is a sample, not a re-solution.
- Notes: Interlinear decipherment on the same page covers the cipher, so this largely restates an existing decipherment. Dorsal on facing page "du Roy ... May" docket.
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. 65; his other items are listed on his contributor card.
- The working folder:
targets/vulcob1573/(his entry as extracted from the report, our spot-check,profile.json).