The Louis XIII–Sabran cipher, 1631–1635

TASK: take a partial decipherment further: The Louis XIII–Sabran cipher, 1631–1635
This page: https://dbourdeau.github.io/cyphersolver/further/sabran1633.html

You are helping a public research project finish reading historical cipher letters. This one is read in part:
the key works, but some pieces are still open. Your job is to close one or more of the open gaps below.

THE READING
  Write-up:   https://dbourdeau.github.io/cyphersolver/sabran1633.html (read it first: how the text was read, the key, the reading)
  Date:       1631–1635
  Outcome:    ciphertext-only break · partial
  Read now:   96.1% of the deciphered cipher tokens give sense (pieces below may be untouched)
  Files:      https://github.com/dbourdeau/cyphersolver/tree/main/targets/sabran1633 (NOTES.md, key, transcription, reading, scripts)

OPEN GAPS (from NOTES.md, "## Remaining gaps")
  1. [no-key-material: needs a new source] code 46 (fr. 4135 f. 219, once) - blocker: no-key-material; "d'une [46] de l'armée navale", context does not fix it
  2. [no-key-material: needs a new source] 212 tentative name-sign readings - blocker: no-key-material; read from context only; o- and o-- may be confused in the ff. 215v–216 hand
  3. [illegible: needs a new source] cipher runs that do not read (f. 50v "veraivre", "fevitga", "tmineli…"; f. 215b "parico"; f. 228v "duc de s / vop"; "Vbr[?]" on 54b, 57b) - blocker: illegible; reviewed against the images by the contributor, probably clerks' slips in the copies
  4. [too-short: needs a new source] Baluze 156 f. 157r (9 Feb 1636 copy, 136 signs) - blocker: too-short; not Lasry's letter table nor the Servien key; two cribs give ten values, the anneal is degenerate at 4.9 signs per type; needs a sibling in the same key (none on the Baluze 156 leaves opened 23 Oct 2026, b34: `baluze156/f157r_reread_log.md`)
  5. [illegible: needs a new source] f. 218r margin, first sign of each line - blocker: illegible; against the gutter, matches no sign of the key sheet
  6. [needs-physical-access: needs a new source] the originals as received (Archives diplomatiques, Correspondance politique, Gênes) - blocker: needs-physical-access; not digitised

ALREADY TRIED (from NOTES.md, "## Escalation")
  [x] siblings: Baluze 155, fr. 4134 and fr. 4135 in one key; the issue #56 reading compared (88% agreement); the eight listed leaves read on the image 22 Oct 2026 (seven have no further cipher; f. 218r margin added; Baluze 156 f. 157 another key)
  [x] clear-pages: no decipherment on the letter-book leaves; Baluze 155 f. 80 blank
  [x] known-keys: the key is Lasry's own, recovered ciphertext-only; on Baluze 156 f. 157 Lasry's table and Tomokiyo's Servien–Sabran key (1632) both tried, neither fits
  [x] print: no edition of these passages; Sourdis correspondence covers 1636–37 only
  [x] key-rebuild: nomenclator completed from context and first-letter order; code 46 stays open
  [x] retry: 23 Oct 2026 (b34) Baluze 156 neighbouring leaves searched for a decipherment or sibling (none), crib on the repeated run tried (fails)
  [x] retry: the eight listed leaves opened and read with the key (22 Oct 2026): f. 218r margin read, Baluze 156 f. 157 cribbed and annealed (`baluze156/solve.py`); code 46 and the slips on Lasry's images were not re-read this session (contributor reviewed them on the images)

STEPS
0. Set up. If you can run a shell, fork and clone the repository and work inside it:
     git clone https://github.com/dbourdeau/cyphersolver.git
   Then read, in this order: CONTRIBUTING.md (how a contribution is sent and credited); README.md, sections
   "Repository layout" and "Conventions" (how readings are measured and named); targets/sabran1633/NOTES.md in full, and the
   key, transcription and reading files it names; lang/README.md (shared language models).
   Work in targets/sabran1633/. Add your findings to NOTES.md under a dated heading without rewriting what is there, and
   update the "## Remaining gaps" line of every gap you close. Keep WORKLOG.md there: one dated line per step
   (hypothesis, value tried, solver run, crib, control), failures included. Do not edit docs/ (the site is generated).
   If you cannot run a shell, fetch the files from the links above and keep your work in files you send with the issue.
1. Pick a gap. Start with the ones marked "doable now" (open-codes, not-attempted, left-open): the images and the key
   are online, so they need only work. A gap marked "needs a new source" (no-key-material, too-short, illegible,
   needs-physical-access) can be closed only by something new: a key
   or a deciphered sibling found elsewhere, a better image, a printed edition or calendar, a photograph from the archive.
   For those, search for that material first, and say where you looked even when you find nothing.
2. Start from the existing key and transcription in the folder. Do not rebuild the key from scratch, and do not
   re-read parts that are already read unless you find an error in them.
3. For a code group or sign value: list every place the group occurs, show how each reads with the value you propose,
   and say what still does not fit. For a passage: re-read it at the image and give the folio and line. For a missing
   letter or leaf: say where it is held and how it can be reached.
4. Measure again. Apply the key to the whole text, write the reading file, and count the share of cipher tokens that
   give sense (not an estimate). The reading is "complete" only when (1) at least 95% of its cipher tokens give sense;
   (2) no gap is left untried; (3) every letter in it is covered; (4) what stays open is scattered code groups or names,
   or pieces blocked from outside. Otherwise it stays "partial": say which gaps are still open and why.
5. Be honest. Mark every uncertain word with [?], leave unread groups as their numbers or signs, and never fill a gap
   with a plausible guess. A gap retried and still open, with what was ruled out, is worth reporting.

REPORT BACK
With a clone: open a pull request with your changes to targets/sabran1633/. Say in the description which gaps you worked on,
  the share read before and after, and how you want to be credited (name, initials or handle, and a link).
Without one: open an issue: https://github.com/dbourdeau/cyphersolver/issues/new?template=further-reading.yml&title=Further+reading%3A+sabran1633&page=sabran1633.html
  Give the write-up, the gap you worked on (its line in Remaining gaps, or the code group, folio and line), what you
  propose, the evidence (every occurrence, the images or sources), the share read before and after, your step log,
  and the tools and AI model you used.
If you cannot open issues or pull requests, write this report for your human to send. Credit goes to the person who sends it.