Solution of Ciphertext of Catherine of Aragon to King Ferdinand (1509)

Back in 2018, I submitted to MTC3 an unsolved ciphertext of Catherine of Aragon to King Ferdinand, her father. My challenge was published on 28 November 2018. To my pleasant surprise, it was quickly solved by two people: Victor and Thomas Bosbach. (I received their solutions by email from MTC3 in December 2018.) When I reported it in my blog at the time, I refrained from disclosing the solution because the contest was still open.

Since more than three years have passed without anyone taking up the challenge, I now present here the solution.

Catherine of Aragon's Cipher Letter

Catherine of Aragon (1485-1536) came to England to be the bride for Arthur, Prince of Wales, but had to live withdrawn and as a virtual prisoner of her father-in-law, Henry VII, after the unexpected death of the prince in 1502. Catherine started using ciphers in 1507 in her correspondence with King Ferdinand, her father. At that time, the use of ciphers was not common at the English court (see another article).

Henry VII died in April 1509 and the late prince's brother, now King Henry VIII, married Catherine in June 1509. On 1 November 1509, Henry wrote to King Ferdinand, reporting, among others, pregnancy of the Queen (CSP, vol.II, p.24), saying "Your daughter, her Serene Highness the Queen, our dearest consort, has conceived in her womb a living child and is right heavy therewith." (Other known letters between them from this period are given in References.)

The unsolved ciphertext in question is Catherine of Aragon's letter from 3 November 1509 to King Ferdinand, available on line at the Spanish archives (PARES, Ref: ES.47161.AGS//PTR,LEG,54,51) under the title "Carta de la Reina de Inglaterra, Catalina de Aragon, al Rey Catolico quejandose mucho de lo que ha escrito Manuel de Esquivel de su Confesor".

The cipherext is followed by a cleartext, which begins with "Suplyco a Vuestra Alteza que me perdone porque las cyfras no van de my mano, que my yndespusycyon me quyta el tyenpo que para escrevyllas e menester. Y por ser tanto y por no azer mas esperar al correo, yze a my confesor y chancyller que las yzyese" (the transcription taken from Nicolás Ávila Seoane, "La escritura de las reinas de Portugal Isabel y María hijas de los Reyes Católicos" (pdf). From this apology of not writing the ciphertext in her hand, this cleartext is not a decipherment of the ciphertext.

Deciphered Text

The solutions independently submitted by Victor and Thomas Bosbach are similar, which indicates they are generally correct. Although I cannot say which is better, I present Thomas Bosbach's solution below. Inevitably, both solutions leave some letter codes undecoded (marked with brackets [ ] below).

Hopefully, someone versed in Spanish can use the text below to complete the plaintext. (To help them critically review the decipherment, the first line in Victor's solution is "Por la echar de la otra carta que va en claro ver a".)

1) Por la ec[ma]a de la otra carta aveva en claro vera
2) vestra alteza a [miz] [tm] [tap] do [tip] a [tcn] culpa de detene-
3) rse si esse coyro [tap] [tm] para querer el Rey mi senor escrevyr
4) a vuestra alteza ? dar le parte [pe4] [nez] [tan] que toca a su perso-
5) na y estado como a verdadero padre y [tnp] que esperava
6) una respuesta que avya escryto al Rey de Francya para
7) [nc] bya?a a vuestra alteza la qual ? tardado [si] que asta [no4]
8) [es] se a podydo despachar este coreo y [naz] es tan de
9) s?rcyada pues la carta que el Rey mi senor le avya escryto
10) av al vuestra altesa vera para la minuta de la sua y de la otra que
11) aquyua que el Rey mi mando que enbrase a vuestra alteza para que
12) vyese la descorts ya y desamor que el embajador (?) le muestr-
13) ayendo tenydo ? amor con su padre que dyos perdo-
14) ne parscyeneold que ahora tiene mucha mas causa
15) [tnp] ser el Rey mi senor hijo de vuestra alteza por averer su
16) amystad mas que con su pader pues la suya [na] fencyd-
17) a y la del Rey le ser ya provechosa pues que el embajador esta
18) seguro que el rey mi senor sy?yra la parte de vuestra alteza
19) y esto es tan ando a [tap] yunto [tm] le podra a el yrvye-
20) n stavyere yr contra [pu4] [nemo] esto dy?o por que seg-
21) un mi paresce se publyca para [njz] Francya como su Rey avyere
22) acer?e ya al Rey mi senor de lo aval el [tm] cura [para] que esta-
23) ndo cyerto como eta de la toda y favor de vuestra alteza [tin] so-
24) la me ne pyensa que [tin] le puede ofender mas que [tap] ?e
25) y aquyyese con el ayuda de dyos y favor de vuestra alteza suyo
26) ra por recentamyento destado de vuestra alteza y suo
27) [nemo] y pues eso esta ? [tap] y asta [no4] [tin] se save mas para que
28) yo pueda escrevyr a vuestra alteza [tap] [tin] suplicarle que
29) l amor que sienpre me a amostrado quyera vuestra alteza
30) que [no4] con el Rey se pareca y pues el es tan verdadero
31) hijo de vuestra alteza que als cosas que as vesta docaren
32) vuestra alteza [tcn] s m yre como cosas suyas propyas pues
33) el a [tap] [tcn] s tyene yol?ara que vuestra alteza dyspon?yde
34) ? as como mas al estado de vuestra alteza pertenescyer
35 ) e para que estn conosce el Rey que mas le con vern y por que
36) yo espero que vuestra alteza a [tap] [tan] aveva ya para [tcp] acera
37) mi senal da merced [tin] dyre al y yosas [tap] [tin] acab-
38) ar esperando el mus de vuestra alteza por poder sver ma-
39) s a menudo nuetas de la salud y prosperydad
40) de vuestra alteza la qual nro. senor acrescyente con mu
41) mchos mas ue y nos y senoryos [mvz] yo deseo

Cipher Used by Catherine of Aragon and King Ferdinand (1509)

Codebreaking

I once had a chance to hear about how Thomas Bosbach solved this. The breakthrough was "tildes" in the ciphertext. He thought the symbol with a tilde might be "n with tilde" in "señor". Indeed, he found all words with a tilde (except on p.2 where "señior" might be abbreviated to "sen.") stood for "señor". From this finding, he could reveal step by step almost all of the symbols representing single letters.

Victor's approach appears to have been different, because some instances of "señor" appear to have been identified in his last stages.

Further Sources Yet to be Located

Since Catherine of Aragon was among the first who used cipher in the English court, I looked for her ciphers. It is known that the Spanish archives have her letters in cipher, but I could not locate them at the time.

For example, Catherine's first letter in cipher appears to have been that of 7 September 1507 (Bergenroth p.426), preserved in S.E.T.c.I. [i.e., Archivo General en Simancas, Estado, Tratados con Inglaterra] L.5.f.57. but I could not locate it online. Catherine's letters of the same date are found at PARES, Ref: ES.47161.AGS//PTR,LEG,54,46 and Ref: ES.47161.AGS//PTR,LEG,54,47, but these seem to be different.

Bergenroth Suppl. p.33 has a letter originally deciphered by Almazan (20 March 1509), preserved in Archivo General de Simancas Patronato Real Tratados con Inglaterra, Legajo No.5 fo.60.

As yet another example, Catherine's letter of 29 July 1509, preserved in Britain, has a short passage in cipher (Brewer).

If any further cipher material related to Catherine of Aragon is available, please let me know.

References:

Bergenroth (ed.), Calendar of State Papers (CSP), Simancas, vol.II, supplement (Note Bergenroth employs the spelling "Katharine".)

(Search with "PTR,LEG,54,DOC" in the field "Signatura" to list the docuents in the same file.)

Carta de Enrique VIII al Rey Catolico rogando interceda para el fin de la guerra con Venecia (1509-11-01) (PARES, Ref: ES.47161.AGS//PTR,LEG,54,101,1)

Carta de Enrique VIII de Inglaterra al Rey Catolico sobre su reciproca amistad y el embarazo de su esposa la Reina (1509-11-01) (PARES, Ref: ES.47161.AGS//PTR,LEG,54,101,2)

Carta del Rey Catolico a la Reina de Inglaterra, Catalina de Aragon, sobre respetar a los venecianos (1509-11-28) (PARES, Ref: ES.47161.AGS//PTR,LEG,54,102)

Carta del Rey Catolico a la Reina de Inglaterra, Catalina de Aragon, sobre una alianza entre Enrique VIII de Inglaterra, Juana I de Castilla, el Principe Carlos, el Emperador Maximiliano I, y el mismo (1509-12-03) (PARES, Ref: ES.47161.AGS//PTR,LEG,54,105)