Röell (attributed) to Van Dedem, 9 February 1809

At a glanceNot solved · text not obtained

The letters: Two numerical-code letters of 13 pages, attributed by DECODE to W. F. Röell: R1469 (7 pages, dated 9 February 1809) and R1470 (6 pages, undated). They are neither addressed nor signed. Röell’s despatches in the archive are in clear Dutch.
Where: Nationaal Archief, The Hague, 1.02.04 legatie Turkije inv. 804; DECODE R1469 (images 6681–6687) and R1470 (6688–6693).
The cipher: 2,585 groups, 931 distinct, none reaching even 1% of the text, so common words have many equivalents. Frequent groups are spread over the whole range, so it is not alphabetical.
How it was tried: It is not the legation’s 1788–93 code (only 30–33% of each crib’s groups occur here, against 28% by chance) and not the ministry’s codes of 1804 and 1808. DECODE and print give no key.
Still open: No group has been decoded. The trailing marks on some groups were not re-transcribed. A key could come from the legation codebook, Croiset’s 1808–09 letters to Röell, or a clear copy of a despatch in this code.

01 The records

R1469 (images 6681–6687): opens “Monsieur” and ends on p. 7 with a paraph. 1,297 groups, 622 distinct.
R1470 (images 6688–6693): a docket on p. 1 read by DECODE as “? 69 Fermer? no? 9?”, then code. 1,288 groups, 707 distinct, the highest 3264.

DECODE already doubts the address: Van Dedem was on his way home when the letter was sent.

Frequencies. The commonest groups are 1390 and 460 (12 each in R1469) and 804, 75, 357, 296 and 394 (10 each in R1470). In a French text de alone is 4–5%, so a group rate of about 1% means heavy homophony. The frequent groups run from 35 to 2920 with no clustering, which excludes a one-part code whose alphabetical ranges could be predicted.
The legation’s 1788–93 code (Van Dedem 1788–99), for which French (R1947, R2053) and Dutch (R2121) decipherments exist. It is a different code. Only 30–33% of each crib’s distinct groups occur here, against 28% by chance, and just 0–5 of each crib’s 30 commonest groups are among the 200 commonest here.
The ministry’s other codes of the period, Van Spaen 1808 (plain groups to 1339) and Fagel 1804 (syllabic groups with clear endings). These are different systems.
Keys and print. The DECODE metadata dump has no key record for this legation or ministry. Colenbrander’s Gedenkstukken V (1806–1810) gave nothing by web search. The inventory of Röell’s papers (NA 2.21.008.78) lists letters from F. G. van Dedem and from S. F. Croiset, both 1808–09, but no cipher.

Both letters in full; no group has been decoded.
The trailing marks on some groups are not in DECODE’s transcription and were not re-transcribed. They may be part of the code.
What could supply the key: the codebook in the legation papers (NA 1.02.04, near inv. 804), Croiset’s 1808–09 letters to Röell (NA 2.21.008.78), or a clear copy of any despatch in this code. Henk Boon, Onze man in Constantinopel (2012), was not checked.

Nationaal Archief, 1.02.04 legatie Turkije, inv. 804; DECODE R1469 and R1470 (login), with the manual transcriptions by SofPe (2020).
Nationaal Archief, 1.02.20 legatie Turkije, inv. 804, 980, 988, 990 (online scans).
Nationaal Archief, 2.21.008.78, papers of W. F. Röell, inventory.
H. T. Colenbrander, Gedenkstukken der algemeene geschiedenis van Nederland van 1795 tot 1840, V (1909).

Parsed groups, parser and notes: targets/roell1809/.