e Z T S + e q T + N Z 46 q · U 46 s N C + T q
los de la señora princesa
q = a · + = e · 46 = r · Z = o · T = s

London → Miguel Pérez de Almazán · letter substitution with homophones (Puebla’s First Cipher) and one Roman-numeral code word · 21 April 1506 · deciphered in part with Tomokiyo’s table

De Puebla to Almazán, London, 21 April 1506

Ferdinand’s ambassador in London wrote to the King’s secretary in cipher about Katharine’s household while Philip and Juana waited to sail; Tomokiyo’s table deciphers four of its passages into Spanish sentences.

Daniel Bourdeau · posted

Method: read with known key · Extent: partial (56% of the cipher)

Contributed by WAINUT (solution, transcription) and Satoshi Tomokiyo (key or decipherment used) · Also credited · Gustav Adolph Bergenroth (key or decipherment used) · Contemporary key or decipherment (key or decipherment used)

At a glanceKnown key applied · partial (56% of the cipher)

The letter
Rodrigo González de Puebla, Ferdinand’s ambassador in England, to Miguel Pérez de Almazán, secretary of the King, from London, 21 April 1506. One page of clear Spanish with cipher passages in lines 11–29, signed by Puebla, and an address leaf.
Where
Archivo General de Simancas, Patronato Real, legajo 54, doc. 78 (foliation 179), on PARES as description 2208120. Catalogue entry 617.
The cipher
One sign for each letter, with a second sign for a, i and u/v, run on without word division; one code word of Puebla’s Great Roman Numeral code (DCCCLXXXVIII, “el Rey de Inglaterra”) occurs three times.
How it was deciphered
With Satoshi Tomokiyo’s reconstruction of Puebla’s First Cipher (Bergenroth’s key no. 6), applied unchanged. Under an Early Modern Spanish language model the decode scores −1.69 per letter; 1,000 shuffled keys score at best −4.73.
What it says
People around the Princess of Wales had her write the letters Puebla encloses, for their own interest; he sees her household “tan bien ataviados que mas no pense ver”; and the greed of certain persons is such that even the treasure of the King of England would not content them.
Still open
The clear text around the cipher, read only in part at the size PARES serves; the fragments of ll. 11–17, which do not yet build sentences; three unread signs; the C-count of the code word.
Credit
Transcription, decipherment and controls by WAINUT (pull request #101, 27 October 2026), done with AI language-model agents and re-read by a second agent. The key is Satoshi Tomokiyo’s reconstruction of Puebla’s First Cipher (cryptiana, “Spanish ciphers”), after Bergenroth’s key no. 6; the code word is from the contemporary key in AGS Patronato Real leg. 52 doc. 33.

01 The letter

The unit has four images on PARES: the letter (image 1), two blank pages, and the address leaf (image 4). The address reads Al muy noble señor el señor Miguell Perez dalmaçan secretario y del consejo del Rey nuestro señor; the endorsement, written across the leaf, gives del doctor de la puebla … xxj … abril 1506, and the date line on the letter itself is de Londres a xxj de abril. The image carries the archive’s watermark PTR,LEG,54,78, a pencilled “PR54-78” and the foliation 179. The PARES id is the one Tomokiyo gives for this letter; the catalogue first had 2208061, which is Puebla’s letter of 15 April 1507.

Philip and Juana, King and Queen of Castile since Isabella’s death, were driven ashore in England in January 1506 on their way from Flanders to Spain, and stayed until late April, when they sailed from Falmouth (Falamua in the Spanish of the time) to La Coruña. The clear opening of the letter says that Puebla had written at length to the King and to Almazán by way of Martín Sánchez de Zamudio, the Bilbao shipowner, and that the King and Queen were waiting for the weather at Falmouth. Those clear readings are uncertain at the size PARES serves and are not part of the reading files.

02 The cipher

Tomokiyo calls it Puebla’s First Cipher and identifies it with Bergenroth’s key no. 6. He reconstructed the table from the letters of 1496–1507 before finding the original, and lists this letter among those that use it, without a reading. The table gives one sign for most letters and two for a, i and u/v: a is written q or M, i is b or a 5-like sign, u and v share a small o with the b of b(v). Several letters are written with the shape of another letter (e for l, g for f, f for g, a for h, R for t), and r is the figure-like sign 46. The transcription names each sign by a short ASCII label (key_first_cipher.tsv), and the decoder works on those labels.

Words that the Great Roman Numeral code holds were written as code words instead. Only one occurs here, three times: DCCCLXXXVIII, “el Rey de Inglaterra” on key image 51 of the contemporary code book (AGS Patronato Real leg. 52 doc. 33). The scribe writes CC and CCC as ligatures distinguished by a small mark, and the mark was not checked on this letter, so the value stays doubtful at every occurrence.

The letters run on without word division. Doubled letters are written twice. One sign in l. 13 (in ra?on) is not in Tomokiyo’s table, and the table has no z: in l. 12 a hooked form of the o-sign seems to stand for it (plazer).

03 How it was deciphered

WAINUT transcribed the cipher passages of lines 11–29 from three-times enlarged crops of the PARES image, 370 signs and three code words, and decoded them with the table unchanged (decode.py). A second agent then re-read lines 14–20, 24–26 and 29 on fresh crops in its own sign labels and reproduced every reading letter by letter, with three corrections: abra quien, not abra bien, in l. 16; a single c in inclusas; and the words va a at the start of the passage in l. 29.

The controls ask whether the table could produce Spanish from these signs by chance.

The decode is therefore not an artefact of the table or of the transcription; what limits the reading is the clear text around it.

04 The passages that read

Lines 18–29, with word division and punctuation added. Clear words of the letter are in plain type where they were transcribed; […] is clear text not transcribed, [?word] a doubtful word and { } the code word.

[…] por aquella gente hazia, por su propio interese, que la princesa me escriviese estas cartas que aqui van inclusas. […]

Los de la señora princesa veo tan bien ataviados que mas no pense ver. Por la codicia de algunas personas [?] [?] es tal que con [?el] tesoro de {el Rey de Inglaterra?}, dudo que se [?contentasen] […]

[…] va a beneficio de natura con este […]

[…] those people brought it about, for their own interest, that the princess wrote me these letters, which go enclosed here. […] I see the lady princess’s people so finely dressed that I did not think to see more. [?For] the greed of certain persons [?] [?] is such that, even with [?the] treasure of {the King of England?}, I doubt they would be [?content] […] is going along at the mercy of chance with this […]

“A beneficio de natura” is a set phrase of the period, “left to nature”, that is to chance: Cisneros’s secretaries write in 1516 that something “no se ha de dexar a beneficio de natura”.

The day after this letter, Katharine wrote to her father from Richmond that her people were ready to ask alms and that she herself was all but naked (CSP Spain I no. 459, 22 April 1506). Puebla, whom she distrusted and blamed for her poverty, tells the King’s secretary in cipher that her household is finely dressed beyond what he expected, and that the letters she writes are prompted by people around her for their own interest. The two letters belong to the long quarrel over Katharine’s maintenance and her dowry after Prince Arthur’s death, in which Puebla took Henry VII’s side often enough for Katharine to call him more the English King’s vassal than Ferdinand’s servant.

05 Lines 11–17

The earlier cipher lines decode as well, but between them are clear words that could not be read, so they do not build sentences. Secure words are y de la partida, de todo el [?aresto], con mucha [?razon], señora princesa, conviene, bien y acrecentamiento, de {el Rey de Inglaterra?} y del principe and abra quien le [?pedir] que ningun malcontentamiento. The departure and the “arrest” may be Philip and Juana’s detention in England and their sailing, and the prince is presumably the Prince of Wales, Henry; with the clear words missing, neither can be confirmed. The decode of these lines is shown in the full texts below as decoded, not read.

The first words, y de la partida, are also in a note Tomokiyo left in the source of his “Spanish ciphers” page next to his entry for this letter (an HTML comment, not shown on the page). He had begun to decipher it and published nothing further.

06 Earlier work and print

No printed text of this letter was found. The searches, all on 27 October 2026:

Not searched: Mattingly’s Catherine of Aragon (1941), which is not available in full text, and HathiTrust, whose full-text search could not be reached. The claim of novelty is limited to the prints above.

07 What remains uncertain

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.

ll. 18-29: the passages that read read in part

De Puebla tells Almazán that people around the Princess of Wales, for their own interest, had her write the letters he encloses; that he sees her household finely dressed beyond expectation; and that the greed of certain persons is such that he doubts even the treasure of [?the King of England] would content them. Written as Philip and Juana were about to sail from England; Katharine's own letter of the next day (CSP I no. 459) says her people were all but naked.

Builds coherent sentences, but under the read bar of 95% of words read as sense (82% here); the holes are marked in the reading.

Transcription

transcription.txt

# AGS, Patronato Real, leg. 54, doc. 78 (PARES description 2208120; viewer show/2208120, 4 images: 1 = text,
# 2-3 blank, 4 = address). Watermark on the PARES image: PTR,LEG,54,78; pencil "PR54-78"; foliation 179.
# De Puebla to Miguel Pérez de Almazán, London, 21 April 1506 (clear date line: "de Londres a xxj de abril de ...";
# endorsement on image 4: "del doctor de la puebla ... xxj ... abril 1506").
# Transcription of the cipher passages of image 1 (1017 x 1413 px, the largest size PARES serves), on 3x crops.
# Line numbers count all lines of the page from the top. Cipher signs in ASCII aliases (key_first_cipher.tsv),
# separated by spaces. Clear words between [[ ]] ([[...]] = clear text not transcribed; (?) = doubtful clear word). A code group of the Great
# Roman Numeral code between { }. x[?] = doubtful sign; ? = sign not read; (S?) = a sign that may be part of a
# descender from the line above.
l.11  [[... quando quisiere ./]] b S + e q U q 46 R b S q
l.12  (S?) + T R Z T R q 46 + T b (S?) + R Z (S?) Z + e q 46 + T R Z [[p. en grand ...]] U e q Z' + 46[?]
l.13  {DCCCLXXXVIII}[?] [[y ...]] C Z N L o C a q 46[?] q ? Z N [[y digo(?)]] Q o + S q e q
l.14  T + N Z 46 q U 46 s N C + T M [[...]] C Z N o b + N + [[...]] p b + N s
l.15  q C 46 + C + N R q L b + N R Z [[y atentam(?) ...]] S + {DCCCLXXXVIII}[?] b S + e U 46 b N
l.16  C s U + [[vno(?)]] q p 46 q Q o b + N e + U + S 46 b Q o + N b N f o N L q e C Z N R + N
l.17  R q L b + N R Z
l.18  [[por aquella gente hazia .]] U Z 46 T o U 46 Z U s Z b N R + 46 + T + Q o + e q U 46 b N C +
l.19  T q L + + T C 46 b o b + T + + T R q T C q 46 R q T Q o + q Q o b o q N b N C e o
l.20  T q T [[...]]
l.24  e Z T S + e M T + N Z 46 q U 46 s N C + T q o + Z R q N p b + N q R q o b q S Z T Q o +
l.25  L q T N Z U + N T + o + 46 [[/ por la]] C Z S s C b q S + q e f o N q T U + 46 T Z N q T ? ?
l.26  + T R q e [[que con el(?)]] R + T Z 46 Z S + {DCCCLXXXVIII}[?] [[dudo que]] T + C Z N R + N R q
l.27  T + N[?] [[...]]
l.29  [[...]] o q q p + N + g b C b Z S + N q R o 46 q C Z N + T R + [[no digo(?) ...]]
Decryption

decryption.txt

# Line-by-line decryption of transcription.txt with key_first_cipher.tsv (decode.py).
# T = transcription, D = decryption. Decoded letters run on without word division (see reading.txt);
# clear text in [[ ]], code values in { }, ? = unread sign, x[?] = doubtful sign, (x) = a sign that may be a descender.

l.11 T  [[... quando quisiere ./]] b S + e q U q 46 R b S q
l.11 D  [[... quando quisiere ./]] idelapartida

l.12 T  (S?) + T R Z T R q 46 + T b (S?) + R Z (S?) Z + e q 46 + T R Z [[p. en grand ...]] U e q Z' + 46[?]
l.12 D  (d)estostaresi(d)eto(d)oelaresto [[p. en grand ...]] plazer[?]

l.13 T  {DCCCLXXXVIII}[?] [[y ...]] C Z N L o C a q 46[?] q ? Z N [[y digo(?)]] Q o + S q e q
l.13 D  {el Rey de Inglaterra?} [[y ...]] conmuchar[?]a?on [[y digo(?)]] quedala

l.14 T  T + N Z 46 q U 46 s N C + T M [[...]] C Z N o b + N + [[...]] p b + N s
l.14 D  senoraprincesa [[...]] conuiene [[...]] bieni

l.15 T  q C 46 + C + N R q L b + N R Z [[y atentam(?) ...]] S + {DCCCLXXXVIII}[?] b S + e U 46 b N
l.15 D  acrecentamiento [[y atentam(?) ...]] de {el Rey de Inglaterra?} idelprin

l.16 T  C s U + [[vno(?)]] q p 46 q Q o b + N e + U + S 46 b Q o + N b N f o N L q e C Z N R + N
l.16 D  cipe [[vno(?)]] abraquienlepedriqueningunmalconten

l.17 T  R q L b + N R Z
l.17 D  tamiento

l.18 T  [[por aquella gente hazia .]] U Z 46 T o U 46 Z U s Z b N R + 46 + T + Q o + e q U 46 b N C +
l.18 D  [[por aquella gente hazia .]] porsupropiointeresequelaprince

l.19 T  T q L + + T C 46 b o b + T + + T R q T C q 46 R q T Q o + q Q o b o q N b N C e o
l.19 D  sameescriuieseestascartasqueaquiuaninclu

l.20 T  T q T [[...]]
l.20 D  sas [[...]]

l.24 T  e Z T S + e M T + N Z 46 q U 46 s N C + T q o + Z R q N p b + N q R q o b q S Z T Q o +
l.24 D  losdelasenoraprincesaueotanbienatauiadosque

l.25 T  L q T N Z U + N T + o + 46 [[/ por la]] C Z S s C b q S + q e f o N q T U + 46 T Z N q T ? ?
l.25 D  masnopenseuer [[/ por la]] codiciadealgunaspersonas??

l.26 T  + T R q e [[que con el(?)]] R + T Z 46 Z S + {DCCCLXXXVIII}[?] [[dudo que]] T + C Z N R + N R q
l.26 D  estal [[que con el(?)]] tesorode {el Rey de Inglaterra?} [[dudo que]] secontenta

l.27 T  T + N[?] [[...]]
l.27 D  sen[?] [[...]]

l.29 T  [[...]] o q q p + N + g b C b Z S + N q R o 46 q C Z N + T R + [[no digo(?) ...]]
l.29 D  [[...]] uaabeneficiodenaturaconeste [[no digo(?) ...]]
Reading

reading.txt

# De Puebla to Almazán, London, 21 April 1506 (AGS PTR leg. 54 doc. 78): cipher passages of ll. 18-29 as sentences.
# From decryption.txt, with word division and punctuation added. Clear words around the cipher are in plain type
# where they were read; [...] = clear text not transcribed. Code values in { }. [?word] = doubtful word,
# [?] = unread word. Line numbers as in transcription.txt.

## Reading

ll. 18-20: [...] por aquella gente hazia, por su propio interese, que la princesa me escriviese estas cartas que aqui
van inclusas. [...]

ll. 24-25: Los de la señora princesa veo tan bien ataviados que mas no pense ver.

ll. 25-27: Por la codicia de algunas personas [?] [?] es tal que con [?el] tesoro de {el Rey de Inglaterra?}, dudo que se
[?contentasen] [...]

l. 29: [...] va a beneficio de natura con este [...]
Translation

translation.txt

# English translation of reading.txt (ll. 18-29), with the same holes.
# l. 29: "a beneficio de natura" is a set phrase of the period, "left to nature / to chance" (Cisneros's secretaries,
# 1516: "no se ha de dexar a beneficio de natura"; CODOIN): revised 27 Oct 2026 from "to the benefit of nature".

## Translation

ll. 18-20: [...] those people brought it about, for their own interest, that the princess wrote me these letters,
which go enclosed here. [...]

ll. 24-25: I see the lady princess's people so finely dressed that I did not think to see more.

ll. 25-27: [?For] the greed of certain persons [?] [?] is such that, even with [?the] treasure of {the King of
England?}, I doubt they would be [?content] [...]

l. 29: [...] is going along at the mercy of chance (a beneficio de natura) with this [...]

ll. 11-17: fragments decoded, not read

A mechanical decode with holes in most sentences: shown so that the transcription and the key can be checked and improved, not as a reading.

Transcription

transcription.txt

# AGS, Patronato Real, leg. 54, doc. 78 (PARES description 2208120; viewer show/2208120, 4 images: 1 = text,
# 2-3 blank, 4 = address). Watermark on the PARES image: PTR,LEG,54,78; pencil "PR54-78"; foliation 179.
# De Puebla to Miguel Pérez de Almazán, London, 21 April 1506 (clear date line: "de Londres a xxj de abril de ...";
# endorsement on image 4: "del doctor de la puebla ... xxj ... abril 1506").
# Transcription of the cipher passages of image 1 (1017 x 1413 px, the largest size PARES serves), on 3x crops.
# Line numbers count all lines of the page from the top. Cipher signs in ASCII aliases (key_first_cipher.tsv),
# separated by spaces. Clear words between [[ ]] ([[...]] = clear text not transcribed; (?) = doubtful clear word). A code group of the Great
# Roman Numeral code between { }. x[?] = doubtful sign; ? = sign not read; (S?) = a sign that may be part of a
# descender from the line above.
l.11  [[... quando quisiere ./]] b S + e q U q 46 R b S q
l.12  (S?) + T R Z T R q 46 + T b (S?) + R Z (S?) Z + e q 46 + T R Z [[p. en grand ...]] U e q Z' + 46[?]
l.13  {DCCCLXXXVIII}[?] [[y ...]] C Z N L o C a q 46[?] q ? Z N [[y digo(?)]] Q o + S q e q
l.14  T + N Z 46 q U 46 s N C + T M [[...]] C Z N o b + N + [[...]] p b + N s
l.15  q C 46 + C + N R q L b + N R Z [[y atentam(?) ...]] S + {DCCCLXXXVIII}[?] b S + e U 46 b N
l.16  C s U + [[vno(?)]] q p 46 q Q o b + N e + U + S 46 b Q o + N b N f o N L q e C Z N R + N
l.17  R q L b + N R Z
l.18  [[por aquella gente hazia .]] U Z 46 T o U 46 Z U s Z b N R + 46 + T + Q o + e q U 46 b N C +
l.19  T q L + + T C 46 b o b + T + + T R q T C q 46 R q T Q o + q Q o b o q N b N C e o
l.20  T q T [[...]]
l.24  e Z T S + e M T + N Z 46 q U 46 s N C + T q o + Z R q N p b + N q R q o b q S Z T Q o +
l.25  L q T N Z U + N T + o + 46 [[/ por la]] C Z S s C b q S + q e f o N q T U + 46 T Z N q T ? ?
l.26  + T R q e [[que con el(?)]] R + T Z 46 Z S + {DCCCLXXXVIII}[?] [[dudo que]] T + C Z N R + N R q
l.27  T + N[?] [[...]]
l.29  [[...]] o q q p + N + g b C b Z S + N q R o 46 q C Z N + T R + [[no digo(?) ...]]
Decryption

decryption.txt

# Line-by-line decryption of transcription.txt with key_first_cipher.tsv (decode.py).
# T = transcription, D = decryption. Decoded letters run on without word division (see reading.txt);
# clear text in [[ ]], code values in { }, ? = unread sign, x[?] = doubtful sign, (x) = a sign that may be a descender.

l.11 T  [[... quando quisiere ./]] b S + e q U q 46 R b S q
l.11 D  [[... quando quisiere ./]] idelapartida

l.12 T  (S?) + T R Z T R q 46 + T b (S?) + R Z (S?) Z + e q 46 + T R Z [[p. en grand ...]] U e q Z' + 46[?]
l.12 D  (d)estostaresi(d)eto(d)oelaresto [[p. en grand ...]] plazer[?]

l.13 T  {DCCCLXXXVIII}[?] [[y ...]] C Z N L o C a q 46[?] q ? Z N [[y digo(?)]] Q o + S q e q
l.13 D  {el Rey de Inglaterra?} [[y ...]] conmuchar[?]a?on [[y digo(?)]] quedala

l.14 T  T + N Z 46 q U 46 s N C + T M [[...]] C Z N o b + N + [[...]] p b + N s
l.14 D  senoraprincesa [[...]] conuiene [[...]] bieni

l.15 T  q C 46 + C + N R q L b + N R Z [[y atentam(?) ...]] S + {DCCCLXXXVIII}[?] b S + e U 46 b N
l.15 D  acrecentamiento [[y atentam(?) ...]] de {el Rey de Inglaterra?} idelprin

l.16 T  C s U + [[vno(?)]] q p 46 q Q o b + N e + U + S 46 b Q o + N b N f o N L q e C Z N R + N
l.16 D  cipe [[vno(?)]] abraquienlepedriqueningunmalconten

l.17 T  R q L b + N R Z
l.17 D  tamiento

l.18 T  [[por aquella gente hazia .]] U Z 46 T o U 46 Z U s Z b N R + 46 + T + Q o + e q U 46 b N C +
l.18 D  [[por aquella gente hazia .]] porsupropiointeresequelaprince

l.19 T  T q L + + T C 46 b o b + T + + T R q T C q 46 R q T Q o + q Q o b o q N b N C e o
l.19 D  sameescriuieseestascartasqueaquiuaninclu

l.20 T  T q T [[...]]
l.20 D  sas [[...]]

l.24 T  e Z T S + e M T + N Z 46 q U 46 s N C + T q o + Z R q N p b + N q R q o b q S Z T Q o +
l.24 D  losdelasenoraprincesaueotanbienatauiadosque

l.25 T  L q T N Z U + N T + o + 46 [[/ por la]] C Z S s C b q S + q e f o N q T U + 46 T Z N q T ? ?
l.25 D  masnopenseuer [[/ por la]] codiciadealgunaspersonas??

l.26 T  + T R q e [[que con el(?)]] R + T Z 46 Z S + {DCCCLXXXVIII}[?] [[dudo que]] T + C Z N R + N R q
l.26 D  estal [[que con el(?)]] tesorode {el Rey de Inglaterra?} [[dudo que]] secontenta

l.27 T  T + N[?] [[...]]
l.27 D  sen[?] [[...]]

l.29 T  [[...]] o q q p + N + g b C b Z S + N q R o 46 q C Z N + T R + [[no digo(?) ...]]
l.29 D  [[...]] uaabeneficiodenaturaconeste [[no digo(?) ...]]
Reading

reading_ll11-17.txt

# De Puebla to Almazán, London, 21 April 1506 (AGS PTR leg. 54 doc. 78): fragments of ll. 11-17 (decoded, not read).
# From decryption.txt, with word division and punctuation added. Clear words around the cipher are in plain type
# where they were read; [...] = clear text not transcribed. Code values in { }. [?word] = doubtful word,
# [?] = unread word. Line numbers as in transcription.txt.

## Reading

ll. 11-13: [...] quando quisiere. Y de la partida, [?desto] [?stares] y de todo el [?aresto] [...] en grand [...]
[?plazer]. [?el Rey de Inglaterra] [...] con mucha [?razon]. Y [?digo] que [?da] la

ll. 14-17: señora princesa [...] conviene [...] bien y acrecentamiento [...] de {el Rey de Inglaterra?} y del
principe. [?Vno] abra quien le [?pedir] que ningun malcontentamiento [...]
Translation

translation_ll11-17.txt

# English translation of reading_ll11-17.txt, with the same holes.

## Translation

ll. 11-13: [...] when he wishes. And of the departure, [?of this] [?stay] and of the whole [?detention] [...] in great
[...] [?pleasure]. [?the King of England] [...] with much [?reason]. And I [?say] that the [?gives]

ll. 14-17: lady princess [...] it is fitting [...] the good and increase [...] of {the King of England?} and of the
prince. [?One] there will be someone who [?asks] him that no discontent [...]

Key: key_first_cipher.tsv

08 Sources

Files: targets/puebla1506/ (notes, sign-label transcription, the key table, decode.py with its controls, the decryption, the reading and translation). Contributed by WAINUT in pull request #101; reviewed for the site on 27 October 2026. The sibling items in Puebla’s Great Roman Numeral code, the despatches of 28 December 1495 and 21 June 1496, are identified in targets/puebla1495/ and targets/puebla1496/; they were deciphered or summarised long ago and have no page.