Fra Guglielmo Vizani to the Comte de Césy, 1637

01 The letter

The letter is dated “Dall’Isola di S. Principe, 8 8bre 1637” and signed F. Guglielmo Vizani. The address leaf, f. 293v, reads All’Ill.mo … Sig. Conte di Cesy in Constantinopoli, so the recipient is the French ambassador, Philippe de Harlay, comte de Césy. It is in the same volume as a second letter of the same date (f. 294), which has one cipher line. The text is clear Italian with cipher in the lines that matter; eight lines are enciphered, 54 words and 190 signs. The clear parts say that on 30 May the writer’s orders were changed, and that he will say everything once the plague has passed, since he does not want to trust it to the pen.

02 The reading

As read by Satoru (name codes in brackets, unread):

Il signor [231] m’ha mandato a domandare se li quattro mila scuti […] a [31] di monsignor Beria d’ordine di V.E. furono promessi a detto signore, … che è vicino all’ottenere il patiarchato per sé. … [64?] Monsignor Beria spera che tra due mesi sia per esser mutato; il [36] e dattone(?) un suo partiale, e per sua [198] havere l’intento a [227] è incertissimo.

Signor [231] sent to ask whether the four thousand scudi […] to [31] of Monsignor Beria were promised, by Your Excellency’s order, to the said lord, who is close to obtaining the Patriarchate for himself. … Monsignor Beria hopes that within two months [the Patriarch] will be replaced; [36] … a partisan of his; and whether, through his [198], he can achieve his aim at [227] is most uncertain.

Satoru identifies Beria as Cyril Kontaris of Veroia, backed by Rome and later Patriarch Cyril II. That identification is his; it fits the history he cites: Cyril Lucaris had regained the Patriarchate in March 1637, Kontaris took office on 20 June 1638, and Lucaris was strangled a week later. His reading of the cipher line on f. 294 (“il Veria … sia lontano”, with the same key) was not checked here.

03 The cipher

A homophonic symbol cipher. Words are divided by a stroke. The vowels have two or three signs, most consonants one or two. There are signs for tt and ss, word signs for il and che, and numeric name codes. Letters that differ only by a dot or a stroke on the original were separated by Satoru on the enlarged image (Ω̇ = i against Ω = g, ∸ = o against ÷ = h, + = c against † = l).

Glyph shapes are approximated with look-alike characters, as on Satoru’s page. Name codes written as numbers: 31, 36, 64?, 198, 227, 231.

04 How it was read, and what was checked

How. Satoru cut the eight cipher lines from the Gallica image (8674×6462 px), transcribed them sign by sign, and had Claude recover the key from the ciphertext alone by simulated annealing scored against Italian four-grams with word boundaries (a model built from I promessi sposi) and a word list. Five of eight random seeds converged on the same reading. No existing key or decipherment was used.

Checks here, none of which repeats his search:

• Re-decoding. His key applied to his 54 transcribed words (dec.py) gives the plain he lists for 46 of 48 words. The other two, both monsignor, lose an s and an n in his glyph strings (an abbreviation, or a slip in the transcription); the rest are name codes.
• A control. The decode scores −1.78 per letter under a model of sixteenth-century Italian, against −4.30 for the best of 200 keys of the same shape with the letters shuffled among the sign classes (mean −5.30). Under a modern Italian model the figures are −1.99 against −6.66.
• The image. The first nine words of line 1 (il signor [231] m’ha mandato …) agree with the Gallica image sign by sign, and the code 64 before the second Monsignor Beria is two digits, as he has it. The rest was not compared by eye.
• His own controls, taken from his page and not re-run: 16 synthetic ciphers of the same size were solved in 15 cases (97–100% of letters); 24 shuffles of the text scored −1294 to −1236 against −1073.7 for the real one.

05 What remains open

• The six name codes: 31, 36, 64?, 198, 227, 231. Candidates are the Patriarch, an Ottoman official, the Mufti; none is confirmed. Césy’s minutes for 1637–38 (BnF fr. 16154–16155) are microfilm only, and no Vizani or Césy code list is known.
• Two unread signs (the word after se and the one after scuti) and the queried dattone.
• An independent transcription from the image. This page rests on Satoru’s; two glyph strings in it are a letter short, and his page says 53 words where it lists 54.
• With the name codes, the unread signs and the queried words as holes, the reading builds coherent sentences but reads at 92.6% of its words (measured 24 October 2026), under the 95% a complete reading needs, so its extent is partial.

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.

BnF fr. 16158 f. 292, Vizani to the Comte de Césy, Prinkipo, 8 Oct 1637 read in part

Fra Guglielmo Vizani writes from Prinkipo to the French ambassador at Constantinople: a person in code asks whether 4,000 scudi were promised by the ambassador's order, and 'Monsignor Beria' (by Satoru's identification Cyril Kontaris of Veroia) is close to obtaining the Patriarchate and hopes for a change within two months; Kontaris replaced Lucaris in June 1638.

Builds coherent sentences, but under the read bar of 95% of words read as sense (93% here); the holes are marked in the reading.

# Vizani to the Comte de Cesy, Prinkipo 8 Oct 1637, BnF fr. 16158 f. 292 (Gallica btv1b9061541x, view 295): the 53 cipher words, glyph by glyph.
# Source: Satoru, https://satoru.net/crypt/vizani/ (published 1 Oct 2026), transcribed with Claude from the Gallica image; glyph shapes are approximated with look-alike characters.
# columns: cipher word (signs run together; digits = name codes) <TAB> plain as read on that page <TAB> flag (n = name code, q = uncertain)
Φ	il	
⊢Ω̇Ωȼ∸⊣	signor	
231	[231]	n
ꝗ	m'	
÷⌒̇	ha	
ꝗ◇̇ȼɤ⌒̇π∸	mandato	
◇̇	a	
ɤ∸ꝗ◇̇ȼɤ⌒̇⊣ʂ	domandare	
⊢ẻ	se	
ʒ	li?	q
hυ⌒̇ꝏ⊣	quattr(o)	
ꝗΩ̇‡⌒̇	mila	
⊢+υπΩ̇	scuti	
ϑ	?	q
⌒̇	a	
31	[31]	n
ɤΩ̇	di	
ꝗ∸đΩ̇Ωȼ∸⊣	monsignor	
□ʂ⊣Ω̇⌒̇	Beria	
∸ꝏʂȼẻ⊣ʂ	ottenere	
Φ	il	
ʋ⌒̇πΩ̇⌒̇⊣+÷⌒̇π#	patiarchato	
ʋʂ⊣	per	
⊢ẻ	sé	
6ꝗ	[64?]	n
ꝗ∸đ⊢Ω̇Ω∸⊣	monsignor	
□ʂ⊣Ω̇⌒̇	Beria	
⊢ʋʂ⊣◇̇	spera	
⌂	che	
π⊣⌒̇	tra	
ɤυʂ	due	
ꝗʂ⟷Ω̇	mesi	
⊢Ω̇⌒̇	sia	
ʋʂ⊣	per	
ẻƵʂ⊣	esser	
ꝗυπ⌒̇π∸	mutato	
Φ	il	
36	[36]	n
ẻ	e	
ɤ⌒̇ꝏ∸ȼẻ	dattone?	q
υȼ	un	
⊢υ∸	suo	
ʋ⌒̇⊣πΩ̇⌒̇†ẻ	partiale	
ʂ	e	
ʋʂ⊣	per	
⊢υ	su(a)	
198	[198]	n
÷⌒̇υʂ⊣ẻ	havere	
†	l'	
Ω̇ȼπʂȼπ∸	intento	
6	a	
227	[227]	n
ẻ	è	
8ȼ+ʂ⊣π8ƵΩ̇ꝗ∸	incertissimo

# Vizani to Césy, Prinkipo 8 Oct 1637, BnF fr. 16158 f. 292: decipherment

Transcription, key and reading by Satoru (https://satoru.net/crypt/vizani/, 1 Oct 2026); checked here.

## Reading: Satoru's, with the clear text around the cipher (copied verbatim from NOTES.md, 22 Oct 2026)

"Il signor [231] m'ha mandato a domandare se li quattro mila scuti [?] a [31] di monsignor Beria d'ordine di V.E. furono promessi a d(ett)o Sig.r, il quale ... e
vicino all'ottenere il patiarchato per se. ... [64?] Monsignor Beria spera che tra due mesi sia per esser mutato; il [36] e dattone? un suo partiale, e per su(a) [198]
havere l'intento a [227] e incertissimo." The clear passages say that orders changed on 30 May and that nothing can be said by letter while the plague lasts.

## The cipher words only, decoded with key.json (output of dec.py, run 22 Oct 2026; the script's language-model control step did not run offline)

```
differs: ꝗ∸đΩ̇Ωȼ∸⊣ -> monignor, page says monsignor
differs: ꝗ∸đ⊢Ω̇Ω∸⊣ -> monsigor, page says monsignor
54 cipher words; 46 agree with the plain on the page, 2 differ
il signor [231] m ha mandato a domandare se ? quattr mila scuti ? a [31] di monignor beria ottenere il patiarchato per se [64?] monsigor beria spera che tra due mesi sia per esser mutato il [36] e dattone un suo partiale e per su [198] hauere l intento a [227] e incertissimo
190 signs; 33 distinct letter signs; 5 name-code groups ['198', '227', '231', '31', '36']
```

Bracketed numbers are name codes with no key material.

Decryption: vizani

# Vizani to Césy, Prinkipo 8 Oct 1637, BnF fr. 16158 f. 292: decipherment

Transcription, key and reading by Satoru (https://satoru.net/crypt/vizani/, 1 Oct 2026); checked here.

## Reading: Satoru's, with the clear text around the cipher (copied verbatim from NOTES.md, 22 Oct 2026)

"Il signor [231] m'ha mandato a domandare se li quattro mila scuti [?] a [31] di monsignor Beria d'ordine di V.E. furono promessi a d(ett)o Sig.r, il quale ... e
vicino all'ottenere il patiarchato per se. ... [64?] Monsignor Beria spera che tra due mesi sia per esser mutato; il [36] e dattone? un suo partiale, e per su(a) [198]
havere l'intento a [227] e incertissimo." The clear passages say that orders changed on 30 May and that nothing can be said by letter while the plague lasts.

## The cipher words only, decoded with key.json (output of dec.py, run 22 Oct 2026; the script's language-model control step did not run offline)

```
differs: ꝗ∸đΩ̇Ωȼ∸⊣ -> monignor, page says monsignor
differs: ꝗ∸đ⊢Ω̇Ω∸⊣ -> monsigor, page says monsignor
54 cipher words; 46 agree with the plain on the page, 2 differ
il signor [231] m ha mandato a domandare se ? quattr mila scuti ? a [31] di monignor beria ottenere il patiarchato per se [64?] monsigor beria spera che tra due mesi sia per esser mutato il [36] e dattone un suo partiale e per su [198] hauere l intento a [227] e incertissimo
190 signs; 33 distinct letter signs; 5 name-code groups ['198', '227', '231', '31', '36']
```

Bracketed numbers are name codes with no key material.

<!-- English translation of the reading in texts/f292_decryption.md (Claude Opus 5.5, 23 Oct 2026): Satoru's reading of the cipher of BnF fr. 16158 f. 292 with the clear words around it, checked here with key.json. An excerpt (… = text left out there). Same holes: [231], [31], [36], [198], [227] name codes with no key material, [64?] doubtful, [?] unread. -->

# Vizani to the Comte de Césy, Prinkipo, 8 October 1637 (BnF fr. 16158 f. 292): English translation

"Signor [231] has sent to ask me whether the four thousand scudi [?] to [31] of Monsignor Beria, by Your Excellency's
order, were promised to the said Signor, who … is close to obtaining the patriarchate for himself. … [64?] Monsignor
Beria hopes that within two months he will be changed; the [36] has been given(?) to a partisan of his, and for his
[198] to obtain his aim at [227] is most uncertain." The clear passages say that the orders changed on 30 May and that
nothing can be said by letter while the plague lasts.

06 Sources

• Satoru, The Vizani Cipher (1637) Deciphered, 1 October 2026: transcription, key, concordance, controls. Made with Claude (Opus 5.5) under his direction. Also sent by email.
• Bibliothèque nationale de France, Français 16158 ff. 292–294, Gallica.
• Cryptiana, list of unsolved historical ciphers, where the letter is listed.

Notes, his transcription and key, and the decoder with its control: targets/vizani1637/.