Unsolved Catalogue · no. 2542 · class A · priority 4.9 · open

Peder Charisius (Danish resident at The Hague) → a minister ('Monsieur'): one-page German letter with eleven passages in signs and numbers, no decipherment

Charisius's private word to Copenhagen in June 1655 on Dutch naval measures and England, in the months before the Swedish attack on Poland.

Date
7 June [1655] (year from the archive folder 'Peder Charisius 1655'; the leaf gives day and month only)
Correspondents
Peder Charisius → an unnamed minister in Copenhagen ('Monsieur')
Place
The Hague
Language
German
Held at
Rigsarkivet (Copenhagen), Tyske Kancelli, Udenrigske Afdeling (TKUA), Speciel del, Nederlandene: B.44, 1646-59, Gesandtskabsrelationer, til dels med bilag, fra Martin Tancke, Peter Christian Roch, Peder Charisius, Henrik Villumsen Rosenvinge og M. Rømer; inner folder 'Relationer fra Resident Peder Charisius 1655' · Arkivalieronline epid 19852699, unit 261381 (633 images), image 441 right-hand page: 27 lines, about 95 cipher tokens in eleven passages. Images 442-443 are a copy of the Dutch States-General cipher (key lead); image 444 right is a German letter to 'Herr Resident' in a number cipher, deciphered between the lines.
Images
Arkivalieronline viewer, image 441 · Klingenberg journal 1666, image 433 (sign cipher with marginal plaintext) · Image 442 (Dutch States-General cipher, key lead) · Daisy series record

Hand this page to your AI agent

Give your agent (Claude, ChatGPT or any assistant that can open web pages) this address and ask it to do the task on the page:

https://cyphersolver.com/solve/2542.html

Or copy the block below into the chat. It is the whole task: what the cipher is, where the images are, what has been tried, the steps, and how to report back.

TASK: help read Unsolved Catalogue no. 2542 of the cyphersolver project
This page: https://cyphersolver.com/solve/2542.html

You are helping a public research project read historical cipher letters that nobody has read yet.

THE CIPHER
  Title:          Peder Charisius (Danish resident at The Hague) → a minister ('Monsieur'): one-page German letter with eleven passages in signs and numbers, no decipherment
  Date:           7 June [1655] (year from the archive folder 'Peder Charisius 1655'; the leaf gives day and month only)
  Correspondents: Peder Charisius → an unnamed minister in Copenhagen ('Monsieur')
  Place:          The Hague
  Language:       German (expected)
  Held at:        Rigsarkivet (Copenhagen), Tyske Kancelli, Udenrigske Afdeling (TKUA), Speciel del, Nederlandene: B.44, 1646-59, Gesandtskabsrelationer, til dels med bilag, fra Martin Tancke, Peter Christian Roch, Peder Charisius, Henrik Villumsen Rosenvinge og M. Rømer; inner folder 'Relationer fra Resident Peder Charisius 1655'; Arkivalieronline epid 19852699, unit 261381 (633 images), image 441 right-hand page: 27 lines, about 95 cipher tokens in eleven passages. Images 442-443 are a copy of the Dutch States-General cipher (key lead); image 444 right is a German letter to 'Herr Resident' in a number cipher, deciphered between the lines.
  Images/records:
    - Arkivalieronline viewer, image 441: https://arkivalieronline.rigsarkivet.dk/da/billedviser?epid=19852699#261381,48902531
    - Klingenberg journal 1666, image 433 (sign cipher with marginal plaintext): https://arkivalieronline.rigsarkivet.dk/da/billedviser?epid=23897977#673416,95906962
    - Image 442 (Dutch States-General cipher, key lead): https://arkivalieronline.rigsarkivet.dk/da/billedviser?epid=19852699#261381,48902532
    - Daisy series record: https://daisy.rigsarkivet.dk/arkivserie_detaljer?heid=11841122

WHAT IS KNOWN
  Status: Viewed 11 Nov 2026 at full size. German letter headed 'Monsieur', dated ''s Gravenhag 7 Junij', signed P. Charisius. Passages in a mixed cipher: signs separated by commas (a lambda-like sign, a gamma-like sign, a barred H, y, o, q, d, a cross, a doubled-bar sign) and numbers (10, 14, 25, 42, 50, 61, 103, 124, 128, 144, 145, 183, 202, 235, 272, 283, with 2a and 6a). Nothing over the lines or in the margin. The letter speaks of the 'equipage' made in England and what the Dutch government has resolved 'extraordinari'. The unit was sampled 1 image in 4 (1-633) and images 400-480 every image; this is the only undeciphered cipher seen in it.
  Outcome so far: not yet attempted by the project
  Prior-art check: open (checked 11 Nov 2026: DECODE, Tomokiyo, Fridericia 1894, web)
  Check first: A probable deciphered sibling: Paul Klingenberg's embassy journal of 1665-67 (TKUA Nederlandene, Klingenbergs m.fl.s gesandtskabsarkiv, Journal A; Arkivalieronline epid 23897977, unit 673416, image 433 = pp. 852-853, colour scan) copies passages in a cipher of the same look (cross, double-cross, barred and lambda-like signs, d, q, y, with numbers 10, 14, 42, 109, 134) and gives their meaning in the margin under letters a, b, c ('zur continuation ... Monats subsidien fuer die Lueneb. troupen'). Whether it is the same key as the 1655 letter is not tested. Transcribe the leaf (about 95 tokens). The signs look like a letter alphabet and the numbers like syllables or names; look for the same cipher in Charisius's relations of 1656-60 (unit 261383) and in Peder Vibe's letters to Charisius ('Holland C', cited by Fridericia), where a deciphered sibling may lie.
  Class A: a sibling letter with a decipherment is in the same volume or series, so matching it is the first move.

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); and
   lang/README.md (shared language models).
   Put all your work in targets/<writer><year>/ (a new folder, e.g. sega1593): transcription, key, decipherment, scripts. Write a NOTES.md that says
   what the document is, the system, the key, the reading, and what is open and why. Keep WORKLOG.md there too:
   one dated line per step (transcription, hypothesis, solver run, crib, key found, control), failures included.
   Do not edit docs/ (the site is generated and rebuilt on merge) and do not commit large images: link them.
   If you cannot run a shell, do the same work in files you keep and send them with the issue below.
1. Make sure it is still unread. Search the web and the literature for the shelfmark, the correspondents and the date:
   printed editions and calendars of the correspondence, Satoshi Tomokiyo's cryptiana pages
   (https://cryptiana.web.fc2.com/), the DECODE record and the files attached to it, and the project notes above.
   If a decipherment already exists, stop and report where it is. That is a useful result.
2. Get the images. For Gallica items, a page image is
   https://gallica.bnf.fr/iiif/ark:/12148/<ark>/f<page>/full/full/0/native.jpg (page numbers from the manifest).
   DECODE records (de-crypt.org) need a free account: if you cannot log in, ask your human to download the images for you.
3. Look for key material before attacking the ciphertext, in this order: a decipherment written between the lines or
   in the margin; a clear copy or a deciphered sibling letter in the same volume or DECODE series; a key sheet from the
   same office and years (DECODE key records, Tomokiyo's articles, printed editions); clear passages in the letter
   itself that can serve as a crib.
4. Transcribe exactly what is on the page: one token per sign or number group, line by line, with folio and line
   numbers, unclear signs marked with ?. Keep the transcription as a file. It is worth sending even if nothing else works.
5. If no key exists, identify the system (count the distinct symbols, tokens and repeats: simple or homophonic
   substitution, nomenclator with code words, syllabary, two-digit figures) and recover the key from the ciphertext
   with a solver scored on a language model of the period (German). In the clone, use the shared models in lang/
   (from lang import lm; lm.load('<model>'), lm.best_language(text)) rather than building your own; add a corpus there
   if none fits. Before trusting a result, run the same solver on a control text you encipher yourself in the same
   system and at the same length. If it cannot solve the control, its output on the real letter means nothing.
6. Measure the result against the project's bar (README.md, Conventions). A text is "complete" only when (1) at least
   95% of its cipher tokens give sense, counted from a reading file, not estimated; (2) no gap is left untried;
   (3) every letter in the item is covered; (4) what stays open is scattered code groups or names, or pieces blocked
   from outside (no key material, too short, illegible, needs the archive). Otherwise it is "partial": say which
   pieces are open and why. Mark every uncertain word with [?] and leave unread groups as their numbers or signs.
   Never fill gaps with plausible guesses. A failed attempt that records what was ruled out is still a contribution.
7. Name how the text was obtained with one of the project's methods (do not write just "solved" or "read"):
     - ciphertext-only break: The key was rebuilt from the ciphertext alone: frequencies, solvers, pattern words, the order of the key. No plaintext and no existing key was used. If someone had solved the same text earlier and it was found only afterwards, the write-up says so: an independent re-solution.
     - key from external plaintext: The key was rebuilt by matching the ciphertext against a plaintext found elsewhere: a printed edition, a calendar of state papers, a copy of the same letter in another archive.
     - key from adjacent plaintext: The key was rebuilt from plaintext next to the ciphertext: a partial decipherment written between the lines or in the margin, clear passages in the same letter, a deciphered copy in the same file.
     - external key matched: An existing key that had not been connected with this document (a key for another correspondent or series, a key sheet filed elsewhere) was found to fit, and applied.
     - known key applied: The key was already identified for this document or its correspondence (on its archive or DECODE record, published for it, filed with it) and was applied. The work is transcription and decipherment, which is not mechanical when the key is polyphonic or variable-length.
     - existing decipherment: A complete decipherment already existed (between the lines, on a separate copy, or in print). The work was transcribing the cipher and checking the decipherment against it.
     - not solved: Attempted; neither the key nor the text was obtained. What was learned is recorded. A target whose key was obtained but whose text does not read keeps the method that obtained the key, with extent "none (text not read)".
     - not applicable: Not a cipher (clear text, shorthand, a key sheet, instructions), or the item could not be reached.

REPORT BACK
With a clone: open a pull request with your targets/<writer><year>/ folder. Say in the description how you want to be
  credited (name, initials or handle, and a link) and include the same points as the issue below.
Without one: open an issue: https://github.com/dbourdeau/cyphersolver/issues/new?template=solution.yml&title=Solution%3A+catalogue+2542&target=catalogue+2542
(other kinds of contribution: https://github.com/dbourdeau/cyphersolver/issues/new/choose). Include:
  - Target: catalogue 2542
  - the documents and the images you worked from;
  - the key: sign-to-value table, code groups with values, nulls;
  - the decipherment line by line against the ciphertext, with uncertain passages marked;
  - the method (step 7), the share of tokens that give sense, complete or partial (step 6), and whether the
    reading was already published anywhere;
  - your step log (WORKLOG.md), and the tools and the 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.

Where the cipher is

Cipher located and confirmed. Black-and-white microfilm. German in Charisius's hand with passages of comma-separated signs and numbers; the spaces between the lines and the margins are blank, and the leaves before and after (a Dutch letter, the States-General key copy) carry no decipherment of it. (Arkivalieronline epid 19852699, unit 261381, image 441 downloaded at full size (api.rigsarkivet.dk/ao/v1/images/48902531) and read as a crop 1100 px wide; images 434-448 at 1000 px; checked 2026-11-11 by claude cloud sweep 11 Nov tkua_paging_3)

What is known

Status and prior art. Viewed 11 Nov 2026 at full size. German letter headed 'Monsieur', dated ''s Gravenhag 7 Junij', signed P. Charisius. Passages in a mixed cipher: signs separated by commas (a lambda-like sign, a gamma-like sign, a barred H, y, o, q, d, a cross, a doubled-bar sign) and numbers (10, 14, 25, 42, 50, 61, 103, 124, 128, 144, 145, 183, 202, 235, 272, 283, with 2a and 6a). Nothing over the lines or in the margin. The letter speaks of the 'equipage' made in England and what the Dutch government has resolved 'extraordinari'. The unit was sampled 1 image in 4 (1-633) and images 400-480 every image; this is the only undeciphered cipher seen in it.

Outcome so far. Not yet attempted by the project. Prior-art check: open (checked 11 Nov 2026: DECODE, Tomokiyo, Fridericia 1894, web).

Check first. A probable deciphered sibling: Paul Klingenberg's embassy journal of 1665-67 (TKUA Nederlandene, Klingenbergs m.fl.s gesandtskabsarkiv, Journal A; Arkivalieronline epid 23897977, unit 673416, image 433 = pp. 852-853, colour scan) copies passages in a cipher of the same look (cross, double-cross, barred and lambda-like signs, d, q, y, with numbers 10, 14, 42, 109, 134) and gives their meaning in the margin under letters a, b, c ('zur continuation ... Monats subsidien fuer die Lueneb. troupen'). Whether it is the same key as the 1655 letter is not tested. Transcribe the leaf (about 95 tokens). The signs look like a letter alphabet and the numbers like syllables or names; look for the same cipher in Charisius's relations of 1656-60 (unit 261383) and in Peder Vibe's letters to Charisius ('Holland C', cited by Fridericia), where a deciphered sibling may lie.

Scores

Importance
2 of 5
Solvability
4 of 5
Difficulty
3 of 5
Class A
a sibling letter with a decipherment is in the same volume or series, so matching it is the first move
Note
Scored from the scan during the third TKUA paging pass of 11 Nov 2026 (research/sweep_2026-11-11_tkua_paging_3/); the leaf at full size

Send a result

A reading, a partial reading, a transcription, or a source that shows it was read long ago: all of it counts and is credited to you on the site.

Open a solution issueOther kinds of reportHow credit works← All unsolved ciphers