At a glanceKey from adjacent plaintext · complete
- The document
- A copy, signed "Pour copie Champigny", of the notice that Commodore Charles Knowles circulated on Dominica in the summer of 1744. Jacques-Charles Bochart de Champigny, governor general of the Windward Islands, enclosed it with his letter of 17 August 1744 to Maurepas, the Navy minister.
- Where
- Archives nationales d'outre-mer, Aix-en-Provence, COL C8 A 56 fols. 57–57v (images FRANOM23_C8A_056_0103–0104). The inventory says of the letter that part of it was not decrypted. Not on DECODE.
- The cipher
- The Navy code of the Windward Islands: about 500 numbers for syllables, letters and a few words, with several numbers for common syllables, in no alphabetical order.
- How it was deciphered
- Brice Dudout aligned the code against the interlinear glosses of six letters of Champigny of 1744, froze it, and tested it on a seventh, which it reproduced at 0.894 of characters, against 0.578 at most for shuffled keys. Applied to the enclosure, it gives sentences.
- What it says
- Knowles promises protection to the inhabitants of Dominica "as if they were of his own nation" as long as they stay neutral, demands the return of his deserters at four louis d'or a head, and threatens to treat anyone who hides them as an enemy.
- Still open
- One word of 155 (group 320, "agissent" or "obéissent"); 5 words restored from the sense and 7 probable.
- Credit
- Brice Dudout (Europe chiffrée), working with Claude Opus 5.5: the key, its held-out test, the transcription, the French text and the English translation. His write-up.
01 The notice
In the summer of 1744 the war between France and Britain reached the West Indies. Commodore Charles Knowles anchored at Dominica, an island that both powers treated as neutral, and circulated a notice to its inhabitants. Champigny's letter of 17 August, glossed between the lines in Versailles, tells of Knowles's arrival at the Grande Anse with the Superbe, two 50-gun ships and frigates, of his sailors deserting to Martinique, and of an attack on Saint Lucia that was feared. It announces a copy of the writing Knowles had circulated "to offer the inhabitants of that island a neutrality, which they did not accept".
That copy is the enclosure on fols. 57–57v: 48 manuscript lines of numbers, 381 groups in all, with a few numbers underlined for figures that are meant as figures. The letter was deciphered at the ministry; the enclosure never was, and the ANOM inventory records that part of the letter "has not been decrypted". The key sheet is not in the file.
No image of the leaf is reproduced here: the ANOM viewer states no reuse licence and could not be reached by script, so the strip at the top is set from Brice Dudout's transcription.
02 The cipher
The code is a numerical nomenclator of about 500 values (1–500), two-part, so that nothing in the order of the numbers tells you what they mean. Most values are syllables and letters, spelling the text out in pieces (276 187 = ch-ef), and a few are words: 205 is Dominique, 474 Royal, 3 trois. Frequent syllables have several numbers each. Numbers written in clear and underlined stand for themselves, as the "4 louis d'or" of the notice does.
It is not the code of 1761 rebuilt by Daniel Bourdeau (Mercier 1761), nor the d'Ennery form of 1765, nor the Guiana code of 1744–1762: the three agree with it on none, one and none of the numbers they share with it.
03 How the key was built
The key, called K5 in the notes, was built only from the contemporary interlinear glosses of six letters of Champigny of 1744 in the same volume (C8 A 56 fols. 40, 44, 54–56v, 59, 63 and 67), about 4,900 groups aligned automatically to their glosses, with four written decisions on ambiguous groups (393 = i, 296 = ro, 465 = qu, 300 = fa). It was frozen, its SHA-256 recorded, before the validation letter was opened.
The test was a seventh glossed letter never used before the freeze, fol. 79 of 17 November 1744: 566 groups and 263 words of gloss. Against the gloss, with a measure fixed in advance, the key reaches 0.894 of characters and 0.814 of words; 200 control keys, with the values shuffled between groups, reach 0.578 and 0.122 at most. The criterion (0.85 and 0.75, above every control) was met. Three earlier tests with poorer keys on other letters had stayed below it, at 0.76–0.81 and 0.65–0.74.
04 The reading
The 381 groups give 155 words of French:
M. [Knowles], chef d'escadre de Sa [Majesté] {Britannique}, fait savoir à tous les {habitans} de l'isle de la Dominique que, pendant qu'ils demeureront dans une parfaite neutralité, qu'ils peuvent être assurés de sa protection en toute manière, comme s'ils étoient de sa propre nation, ayant bien soin d'{empêcher} toute insulte et pillage qui pourroient leur [arriver] par les corsaires ou autres vaisseaux {armés} ; mais aussi de la part des habitans de l'isle de la Dominique, il demande [absolument] [d'eux] la restitution de tous les gens de son équipage qui ont déjà ou pourront déserter des vaisseaux, et pour comble de récompense il promet de donner pour chaque homme déserté du bord de son escadre 4 louis d'or ; mais si d'autre manière ils cachent aucun de ses gens pour {empêcher} leur restitution, ils peuvent être assurés qu'ils seront {traités} comme des ennemis ; mais s'ils ‹320›issent comme il {demande}, ils peuvent être assurés de sa protection.
Braces mark a probable reading, square brackets a word restored from the sense, angle quotes a group left unresolved. Mr Knowles, commodore of His Britannic Majesty, makes known to all the inhabitants of Dominica that while they stay perfectly neutral they may count on his protection in every way, as if they were of his own nation, and that he will see to it that privateers and other armed ships do them no harm. In return he demands that they give back every man of his crew who has deserted or may desert, and promises, "as a crowning reward", four louis d'or for each man deserted from his squadron. Those who hide his men to prevent their return will be treated as enemies; those who do as he asks keep his protection.
To Brice Dudout's knowledge this is the first published decipherment of the enclosure.
05 What remains uncertain
- Unresolved, 1 word. "s'ils ‹320›issent comme il demande": agissent (act) or obéissent (obey). Group 320 occurs in none of the seven glossed letters examined. Either reading gives the same sense.
- Restored from the sense, 5 words. Knowles: 381 251 326 110 217 301 (elsewhere the name is 381 25 326 110 217, with 25 = K, so 251 is probably a malformed 25). Majesté: number 222, absent from every glossed letter, the only word that fits "Sa … Britannique". arriver: 300 (fa) written for 303 (ve), neighbouring numbers. absolument: 470, not in the glosses. d'eux: 336 306 428 = ce eu x, which would make "il demande absolument ce eux la restitution" ungrammatical.
- Probable, 7 words. Britannique (391 standing for -mbr- in "nombre"), habitans (253 followed by 436 instead of 435, neighbours), empêcher twice (296 = ro in 35 of 35 glossed cases, so the sense is relied on), armés (254 with a number seen once), traités (204 = tr in a September letter) and demande (433, one doubtful alignment).
- Control. The held-out test is on a letter of the same year and volume. The enclosure has no gloss of its own, so the reading itself is checked by the sense and by the four louis d'or, the neutrality and the deserters that Champigny's glossed letter reports.
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.
Knowles's neutrality notice to the inhabitants of Dominica, cipher copy enclosed by Champigny, 17 Aug 1744
Protection for inhabitants who stay neutral; four louis d'or per deserter returned; those who hide deserters will be treated as enemies.
Transcription
# ANOM (Aix-en-Provence), COL C8 A 56 fols. 57-57v, enclosure ("Copie", signed "Pour copie Champigny") of
# Champigny to the minister, Fort-Royal, 17 August 1744. One line = one manuscript line. "4" = number in clear (underlined).
# fol. 57 = lines 1-32, fol. 57v = lines 33-48. Images (IREL FRANOM23_C8A_056_0103-0104) not included: no reuse licence.
1 381 251 326 110 217 301 276 187 27 172
2 239 448 222 391 112 107 435 498 462 300
3 19 107 288 13 256 213 375 301 253 436
4 213 239 217 117 239 205 462 467 294 301
5 239 99 306 458 296 461 380 28 20 145
6 300 112 54 215 306 223 52 209 54 294
7 301 241 306 303 461 437 458 304 301
8 50 458 441 239 448 86 296 54 23
9 365 255 256 218 417 498 81 458 150
10 77 500 246 32 301 261 41 239 448
11 241 296 86 458 134 365 304 191 435
12 107 30 102 281 27 96 271 296 81
13 55 256 218 281 50 38 54 261 226
14 217 456 325 465 393 368 130 41
15 495 13 55 335 300 130 145 375 213
16 150 55 448 112 458 301 140 21 28
17 223 458 213 56 347 254 180 417 393
18 301 304 110 301 246 239 456 145
19 107 239 301 253 435 217 239 38
20 117 239 205 32 239 77 435 239
21 470 102 346 75 336 306 428
22 456 458 213 151 352 493 239
23 256 301 375 213 272 239 301
24 243 218 465 19 438 325 465
25 112 243 107 239 200 140 368 296
26 461 239 351 55 54 130 239 301
27 471 56 347 261 368 150 99 310
28 239 458 150 77 241 255 336 32
29 86 296 500 107 239 90 8 20
30 55 368 276 13 462 175 239
31 351 130 54 328 98 55 27
32 239 301 243 378 4_ 411 257
33 213 27 126 417 19 301 246
34 350 13 28 107 458 417 498
35 81 458 32 213 289 276 255
36 223 21 386 48 8 243 239 301
37 471 272 368 96 271 296 81
38 130 495 458 213 151 352 493
39 32 301 241 306 303 461 437
40 458 304 301 50 458 441 294
41 213 351 296 461 204 183 150
42 99 500 239 213 419 301 417
43 112 301 213 32 301 320 393
44 213 351 461 150 99 77 81 32
45 239 426 433 239 32 213 241
46 306 303 461 437 458 13 213
47 50 458 441 239 448 86 296
48 54 23 493Decryption
# Group-by-group decryption with the frozen key key.tsv (K5, SHA-256 db2f99ee...). # <n> = group absent from the key; "?" = value seen with share < 0.6 in the glosses; [4] = number in clear. ## line 1 381 251 326 110 217 301 276 187 27 172 m.al?.no.u.l.s.ch.ef.d.escadre ## line 2 239 448 222 391 112 107 435 498 462 300 de.sa.<222>.mb.i.t.an.ni.que.fa ## line 3 19 107 288 13 256 213 375 301 253 436 i.t.savoir?.a.tou?.s.le.s.habita?.ga ## line 4 213 239 217 117 239 205 462 467 294 301 s.de.l.isle.de.ladominique.que.pendant.quil.s ## line 5 239 99 306 458 296 461 380 28 20 145 de.m.eu.re.ro.nt.dans.u.ne.par ## line 6 300 112 54 215 306 223 52 209 54 294 fa.i.te.n.eu.t.ra.li.te.quil ## line 7 301 241 306 303 461 437 458 304 301 s.p.eu.ve.nt.est.re.a.s ## line 8 50 458 441 239 448 86 296 54 23 su.re.s?.de.sa.p.ro.te.c ## line 9 365 255 256 218 417 498 81 458 150 tion.en.tou?.e.ma.ni.e.re.co ## line 10 77 500 246 32 301 261 41 239 448 m?.me.si.il.s.et.oient.de.sa ## line 11 241 296 86 458 134 365 304 191 435 p.ro.p.re.na.tion.a.y.an ## line 12 107 30 102 281 27 96 271 296 81 t.bien?.so.in.d.em.pe.ro.e ## line 13 55 256 218 281 50 38 54 261 226 r.tou?.e.in.su.l.te.et.pi ## line 14 217 456 325 465 393 368 130 41 l.la.ge.qu.i.pour.r.oient ## line 15 495 13 55 335 300 130 145 375 213 leur.a.r.ri.fa.r.par.le.s ## line 16 150 55 448 112 458 301 140 21 28 co.r.sa.i.re.s.ou.a.u ## line 17 223 458 213 56 347 254 180 417 393 t.re.s.va.x?.ar.u.ma.i ## line 18 301 304 110 301 246 239 456 145 s.a.u.s.si.de.la.par ## line 19 107 239 301 253 435 217 239 38 t.de.s.habita?.an.l.de.l ## line 20 117 239 205 32 239 77 435 239 isle.de.ladominique.il.de.m?.an.de ## line 21 470 102 346 75 336 306 428 <470>.so.lu.ment.ce.eu.x? ## line 22 456 458 213 151 352 493 239 la.re.s.ti.tu.tion.de ## line 23 256 301 375 213 272 239 301 tou?.s.le.s.gens.de.s ## line 24 243 218 465 19 438 325 465 on.e.qu.i.pa.ge.qu ## line 25 112 243 107 239 200 140 368 296 i.on.t.de.ja.ou.pour.ro ## line 26 461 239 351 55 54 130 239 301 nt.de.se.r.te.r.de.s ## line 27 471 56 347 261 368 150 99 310 es.va.x?.et.pour.co.m.ble? ## line 28 239 458 150 77 241 255 336 32 de.re.co.m?.p.en.ce.il ## line 29 86 296 500 107 239 90 8 20 p.ro.me.t.de.do.n.ne ## line 30 55 368 276 13 462 175 239 r.pour.ch.a.que.homme.de ## line 31 351 130 54 328 98 55 27 se.r.te.du.bo.r.d ## line 32 239 301 243 378 4_ 411 257 de.s.on.escadre.[4].lo.vi? ## line 33 213 27 126 417 19 301 246 s.d.or.ma.i.s.si ## line 34 350 13 28 107 458 417 498 d.a.u.t.re.ma.ni ## line 35 81 458 32 213 289 276 255 e.re.il.s.ca.ch.en ## line 36 223 21 386 48 8 243 239 301 t.a.u.cu.n.on.de.s ## line 37 471 272 368 96 271 296 81 es.gens.pour.em.pe.ro.e ## line 38 130 495 458 213 151 352 493 r.leur.re.s.ti.tu.tion ## line 39 32 301 241 306 303 461 437 il.s.p.eu.ve.nt.est ## line 40 458 304 301 50 458 441 294 re.a.s.su.re.s?.quil ## line 41 213 351 296 461 204 183 150 s.se.ro.nt.tr.s.co ## line 42 99 500 239 213 419 301 417 m.me.de.s.nnemy.s.ma ## line 43 112 301 213 32 301 320 393 i.s.s.il.s.<320>.i ## line 44 213 351 461 150 99 77 81 32 s.se.nt.co.m.m?.e.il ## line 45 239 426 433 239 32 213 241 de.m.garnison.de.il.s.p ## line 46 306 303 461 437 458 13 213 eu.ve.nt.est.re.a.s ## line 47 50 458 441 239 448 86 296 su.re.s?.de.sa.p.ro ## line 48 54 23 493 te.c.tion
Reading
# Established text (French)
{x} probable; [x] restored from the sense; ‹x› unresolved (group number given).
M. [Knowles], chef d’escadre de Sa [Majesté] {Britannique}, fait savoir à tous les {habitans} de l’isle de la Dominique que, pendant qu’ils demeureront dans une parfaite neutralité, qu’ils peuvent être assurés de sa protection en toute manière, comme s’ils étoient de sa propre nation, ayant bien soin d’{empêcher} toute insulte et pillage qui pourroient leur [arriver] par les corsaires ou autres vaisseaux {armés} ;
mais aussi de la part des habitans de l’isle de la Dominique, il demande [absolument] [d’eux] la restitution de tous les gens de son équipage qui ont déjà ou pourront déserter des vaisseaux, et pour comble de récompense il promet de donner pour chaque homme déserté du bord de son escadre 4 louis d’or ;
mais si d’autre manière ils cachent aucun de ses gens pour {empêcher} leur restitution, ils peuvent être assurés qu’ils seront {traités} comme des ennemis ; mais s’ils ‹320›issent comme il {demande}, ils peuvent être assurés de sa protection.Translation
# English translation Mr Knowles, commodore of His Britannic Majesty, makes known to all the inhabitants of the island of Dominica that, as long as they remain in perfect neutrality, they may be assured of his protection in every way, as if they were of his own nation; he will take good care to prevent any insult and plunder that privateers or other armed ships might inflict on them. But on the part of the inhabitants of the island of Dominica, he absolutely demands of them the return of all the men of his crew who have already deserted, or may desert, from the ships; and as a crowning reward he promises to give four louis d’or for every man deserted from on board his squadron. But if in any other way they hide any of his men to prevent their return, they may be assured that they will be treated as enemies; if they [act / obey] as he demands, they may be assured of his protection.
Key: key.tsv
06 Sources
- Archives nationales d'outre-mer, COL C8 A 56 fols. 54–56v (Champigny to Maurepas, Fort-Royal, 17 August 1744, glossed) and fols. 57–57v (the enclosure), images FRANOM23_C8A_056_0103–0104: ANOM record.
- Glossed letters used for the key: C8 A 56 fols. 40, 44, 54–56v, 59, 63, 67; held-out letter fol. 79 (17 November 1744).
- Brice Dudout, Europe chiffrée, Champigny 1744 (2026): text, translation and notes.
- On the people: M. Vergé-Franceschi, Les Officiers généraux de la Marine royale 1715–1774 (1990); É. Taillemite, Dictionnaire des marins français (2002); J.-P. Zanco, Dictionnaire des ministres de la Marine (2011); Dictionary of National Biography 31 (1892) on Knowles.
Folder: targets/champigny1744/ (notes, transcription, line-by-line decryption, the key K5, the French text and the English translation, as contributed by Brice Dudout).