At a glanceNot solved · text not obtained
- The document
- “Copie No 1” and “Copie No 2”, copies of Dutch letters with runs of numbers between clear words, and a page of numbers. DECODE gives the Hereditary Prince Willem Frederik, at Berlin, as sender and William V as recipient.
- Where
- Koninklijk Huisarchief, The Hague, A31 Prins Willem V, inv. 337; DECODE R2236 (listed with no decipherment; 4 pages, photographs of photocopies). Catalogue item 218.
- The cipher
- Numbers up to about 390 in the copies, up to 2835 on the last page, separated by commas, with clear Dutch words between them.
- How it was tried
- Set against the French numbered word list rebuilt from R2237, which decrypts the Prince’s letter R2239 in the same file. The numbers run past that list, and the clear words are Dutch: it is another list.
- Still open
- All of it. No list or decipherment for it was found.
01 The record
Inventory 337 of William V’s papers in the Huisarchief holds three DECODE records filed under the Hereditary Prince. Two belong together: R2237 carries ciphered observations with their contemporary decipherment, and from them the numbered word list was rebuilt that decrypts the Prince’s letter from Berlin of 12 March 1796, R2239 (The Hereditary Prince of Orange from Berlin, 1796, a different cipher, with its own page). The third, R2236, was catalogued with them. It is not in the same list.
The four pages are “Copie No 1” and “Copie No 2”, copies of Dutch letters in which runs of numbers up to about 390 alternate with clear Dutch words, and a page of numbers up to 2835 that bleeds through onto R2237’s first page.
02 What was tried
The list that decrypts R2239 has about 250 entries, French words and phrases, many in alphabetical runs, and a group takes a whole entry, chosen letters of it, or the entry cut by some letters at the front or back. R2236’s numbers run to about 390, and to 2835 on one page, past that list, and its clear words are Dutch where R2237 and R2239 are French. So it is another list, or several. The other Orange ciphers of 1795 on DECODE (R1892, R2242) use a 6×6 square of digits, a different system again. The copies were viewed, not transcribed.
03 What remains
- Both copies and the page of numbers: not read. Blocker: no key material. No list or decipherment for this code was found on the record or in the file.
- A lead not followed: Karl de Leeuw’s article on Johann Friedrich Euler, cryptologist at William V’s court (Cryptologia 25, 2001), cited on the DECODE records, may describe the Dutch lists. It is behind a paywall and was not seen.
04 Sources
- Koninklijk Huisarchief, The Hague, A31 Prins Willem V, inv. 337: DECODE R2236 (images by login); siblings R2237 and R2239.
- K. de Leeuw, “Johann Friedrich Euler (1741–1800): Mathematician and Cryptologist at the Court of the Dutch Stadholder William V”, Cryptologia 25 (2001), 256–274 (not seen).
Notes and profile: targets/r2236/; the word list of R2237/R2239 is in targets/hereditary1796/.