Spanish Ciphers during the Reign of Ferdinand and Isabella

The present article presents Spanish ciphers during the reign of Ferdinand and Isabella. It was originally based on Bergenroth's groundbreaking work of 1862. (Bergenroth succeeded in codebreaking of various different ciphers, including very complex ones.) In 2019, I overhauled it by using materials in the Spanish archives available online (My search of the archives is not exhaustive; there are even letters that are calendared by Bergenroth but I could not find online).

Table of Contents:

Introduction of Cipher to Spain

Codes/Ciphers for Doctor Puebla

Generic Features

Codes/Ciphers with Other Ambassadors in England

Codes/Ciphes with Ambassadors in Italy and the Great Captain



Introduction of Cipher to Spain

Once it was said cipher was introduced to Spain by Miguel Perez de Almazan (Real Academia de la Historia, Bergenroth p.xii). He started his career as an assistant secretary to Fernan Alvarez de Toledo Zapata (Real Academia de la Historia) and soon rose to the place of Secretary, then to that of First Secretary of State (Bergenroth p.xvii-xviii). His taking over the conduct of business from Alvarez brought about a great improvement in style and writing of documents (ibid. p.xii).

While no cipher despatches earlier than 1480 are recorded in Bergenroth's calendar, Spanish ciphers in the 1470s can be found in the Spanish archives now available online. See another article at

Codes/Ciphers for Doctor Puebla

Many ciphers mentioned by Bergenroth are those for Doctor Puebla. Puebla (Real Academia de la Historia) was sent to England late in the year 1487 or early in the year 1488 to negotiate a marriage between Catherine of Aragon and Arthur, Prince of Wales (Bergenroth p.xix). He was recalled to Spain in 1492 but was sent again to England in 1495.

Puebla's Roman Numeral Code (1488) (Bergenroth/Puebla-1)

One early cipher consisted of Roman numerals representing a small number of names and words. It was used during Puebla's first mission in England, e.g., in a letter from Puebla to Ferdinand and Isabella, dated 15 July 1488.

vii Ferdinand
viii Isabella
xi the King of England
xii the Queen of England
xix the King of Portugal
xvii the King of France

xx Brittany
xxi the alliance
xxii marriage
xxvi war
xxvii son
xxviii daughter
xxxv De Puebla

(Needless to say, the original letter was written in Spanish, though, for this particular case, a partially ciphered paragraph is a Latin translation of a clause of Puebla's instructions that he prepared because the English could not understand or speak Spanish.)

This is also recorded in Bergenroth's report in PRO 31/11/11 as no.1.

vii Rey Ferdinand
viii Reyna Isabella
x Infanta Catalina
xi Rey de Inglaterra
xiii lo
xv corte
xvii Rey de Francia
xviii Rey de Romanos
xix Rey de Portugal
xx Bretaña

It is accompanied with the following cipher (called Puebla's 1488 Cipher herein).

Code Words (Preconcerted Language)

Puebla's correspondence also used code words for representing names and keywords. A letter addressed to him in June 1489 included a passage in code words as follows:

"Licenciatus Et Decanus" to Puebla
... A messenger sent by the little duck to the falcon returned a short time ago much pleased with the answer of the falcon. The little duck and the fuzarco are so contented that they say nothing could better piebald than the fly with the falcon. Thus everything is going on well now, and it is in the mar-maid that it will be concluded in favour of the cuckoo and the young eagle.
CSP, Spain, Vol.1 (British History Online); Giles Tremlett, Catherine of Aragon: Spanish Queen (2010) p.142-143

An example from 28 December 1495 is menteiond below.

Puebla's Arabic Numeral Code (1491) (Bergenroth/Puebla-2)

Queen Isabella wrote to Puebla "ambassador in England" on 26 May 1491 (PARES) and told him to explain their situation to Henry VII.

A numerical cipher used in this letter has the following vocabulary (Bergenroth's conjecture based solely on the general meaning of the context) (Bergenroth p.35-37).

3 their Highnesses
(i.e., Ferdinand and Isabella)
4 the King
8 the King of France
9 Madame de Bourbon?
10 the King of England
29 good
38 if
39 no/not
40 ambassadors/embassy
42 at present

64 distrust/peace
72 month
74 additional
78 the Duchess of Brittany
81 the treaty
82 in Brittany
87 troops
88 fortress
89 give
90 conquered
91 losing/lost
92 gained
94 besiege
97 troops
102 Granada
114 succour
136 Brittany
146 now
147 hereafter
156 just
162 sea
163 armies
171 dominions
178 Brittany
188 the King of the Romans
232 but
439 aid

This appears to be the same as the one recorded in Roman numerals in Bergenroth's report in PRO 31/11/11 as no.2.

III Rey Cattolico
VIII Rey de Francia
xix no
cxxxvi Bretaña
clxxviii Duquesa
Lxxxi tratado
Lxxxix comunicar

Letter Code (1494) (Bergenroth/Puebla-3)

In November 1494, a new embassador was sent to England but fell ill on the way. Puebla was sent again in his place in 1495. (Bergenroth p.51 ff.)

The following are recorded in Bergenroth's report in PRO 31/11/11 as no.3.

la Venecia
her Rey
fav no
hep Rey de Inglaterra
ded Rey de Francia
hap Rey de Romanos
fof las
civ Escocia
bud aqui

(Examples of monosyllabic code symbols mentioned by Bergenroth are: "bax" for "ciertamente", "dem" for "gente de armes," "ham" for "Yo, el Rey Catolico," (p.cxxxviii), "hep" for "Dios", "hip" for "Diablo" (p.xlvi), "la" for "Venetin," "dam" for "war", "hop" for "King of England", "feb" for "England", "fib" for "Englishmen," "cov" for "Scotchmen" (memorial sketch p.78))

Probably, this is the same as what I call Puebla's Letter Code below, though there remain a possibility of some variants. (There is a possible discrepancy for the meaning of "hep" (King of England or King of France), but Bergenroth observes that there were encoding errors that confound the King of England with the King of France or the Emperor (memorial p.215-216).)

Puebla's Roman Numeral Code (1495) (Bergenroth/Puebla-4)

The following are recorded in Bergenroth's report in PRO 31/11/11 as no.4.

III papa
IV Rey de Romanos
V Rey Catholico
vi, vii El Rey y la Reina
xiii Rey de Francia
xxxvii Navarra
ccccv liga
ccccxx complio
ccccxxvii tiempo

Bergenroth's informal notes provide additional elements.

3 el papa
4 Rey de Romanos
V altesas
VI VII sus altesas
13 el Rey de francia
16 el Rey de Ynglaterra
20 Ynglaterra
24 Duque de Yorque, Prequin
23 Prequin [Perkin Warbeck, Duke of York]
44 amistad
49 Rey de Inglaterra
69 vos el Doctor de Puebla
76 agora
77 despues
91 bien
101 si
102 no
277 casamiento
278 principe de Gales o principeza Catilina
315 Roma
321 Venesia
405 liga
406 qui?
414 piro
420 complis?
423 entrar
425 porque
427 tiempo
433 aqui

The above matches the instances below from 1488 (memorial p.79). It is wondered whether this code was really used so early.

iv the King of the Romans xxiii Duke of York or Perkin Warbeck

This seems to correspond to the following code used in a letter from Puebla to Ferdinand and Isabella, dated 19 July 1495, (PARES) (Bergenroth p.59).

xvi el Rey vuestras altezas si
xci bien
ciiii aca
cxlii cartas
cxxvi prestamente
cccxi el Cardinal
cccxii privasello
cccxxiiii dispojo de la Yglesia
cccxxv violencia del Papa
cccxxvi restituir al Papa lo suyo
z Papa

The contemporary deciphering of this letter is confusing at places and Bergenroth observes that there seem to be errors in the ciphertext in more than one respect.

Deprecated Use of Cipher

Puebla was urged by his masters to report in common writing, not cipher. Considering the continued use of cipher in these despatches from the Catholic monarchs, the problem was not in the cipher itself.

De Puebla is to communicate all Henry does and all tidings about England and Spain, in common writing, without cipher.
Ferdinand and Isabella to Puebla, 22-24 August 1494, ciphered despatch, the ciphered copy being extant (Bergenroth p.67-69)
But if it be true what you write, that the York is taken prisoner, there is no longer any necessity for what you desire; write therefore soon how this affair has ended, and all other news from England, not in cipher but in common writing.
Ferdinand and Isabella to Puebla, 28 December 1495, draft, a ciphered despatch being extant (Bergenroth p.72-75)

Bergenroth says letters entirely in cipher first occur in the year 1495 and are composed of Roman numerals (p.cxxxvii-cxxxviii).

Puebla's Great Roman Numeral Code (1495) (Bergenroth/Puebla-5)

A full 2400-element code is preserved in the archives (Simancas, PTR,LEG,52,DOC.33, PARES). It employs roman numerals up to 2400. The alphabetical sequence of plaintext equivalents ends at 2351 (a duplicated copy of the elements 1995-2351 is appended). The subsequent portion of 2352-2400 may be an addenda. The elements 2373-2400 are for numerals (see below).

This is called the "great key of Latin numbers used by De Puebla" by Bergenroth (p.cxlii). According to Bergenroth, it is the only one cipher for which a complete key is extant (found during his search) and it was the most used one in the extensive correspondence between Doctor Puebla and the Spanish government (ibid. p.xiii). (For a long time, I thought this cipher (which I called Puebla's Great Cipher) was different from the one used in Alvarez's letter (which I called Alvarez's Great Cipher) because Bergenroth did not mention the key for the latter is extant. But the entries for "con", "el", "y", "por" (almost) match those of the cipher below. So I now think these are the same. When reading Bergenroth's description of ciphers, it should be noted that he counted a cipher table and a code list as different keys. Such a treatment may be justified because they were used in different combinations. For example, Puebla's Letter Code below was usually used with Puebla's Second Cipher but in at least one instance, it was used with Puebla's First Cipher.)

(Paleographical notes: The plaintext words are preceded by a sign like ſ. The code symbols are preceded by a symbol like з (an arrowhead?). There are duplicate copies for two damaged sheets in modern hand by Bergenroth (around 222R and 245R in digital data). Roman numerals with a maximum number of "i" are marked with o, presumably for easy recognition: e.g., iiiio; viiio (viiii is not used)). CC and CCC are in ligature. M is written like "IU" and MM is written like "IIU.")

A partially ciphered letter of 28 December 1495 (Bergenroth p.75-77) employs code symbols with Roman numerals below. (Although it is guised as a commercial letter, it is in the hand of Alvarez and was actually an instruction to Puebla. It refers to the King and Queen of Spain as "the Directors of the Company" and their ambassadors as "factors.")

[C]CCCLXXXVIII with [con]
DLXVIII courier
DCCCLV De Puebla
DCCCXCIIII between England
DCCCCXXVII the Constable of Navarra
DCCCCLII the marriage of Prince Arthur
DCCCCLIII marriage of Princess Katharine
MCCCXXIX and [y]

Puebla's letters to Ferdinand and Isabella, dated 27 August 1498, 25 September 1498, 11 January 1500, 16 June 1500, and as late as 15 April 1507 and 7 September 1507 use the following elements (Bergenroth p.194, 197, 213, 226, 228, 410, 429).

CLXXXV friendship
CCCCXX letters
CCCCXXIII marriage
DCCCLXXV Ferdinand and Isabella
DCCCLXXVIII the Queen of Castile
DCCCLXXXI the King of France
DCCCLXXXVII the King of England
DCCCLXXXVIII the King of England
DCCCLXXXIX the Queen of England
DCCCXC the Prince of Wales
DCCCCXXI the King of Scots
MCCXVIII Archduchess Margaret of Austria
MDLXXXIIII Muy altos y muy poderosos Senors Rey y Reyna, &c. (i.e., Ferdinand and Isabella)

Before I found the key in the archives online, I recovered the following symbols from Isabella's letter to Puebla dated 22 August 1496. (In this letter, "-s" or "-a" is appended to a Roman numeral to indicate inflected forms: dLxxiiiis "cosas", mdcLa: "nuestra")

CCCCXXVIcasaMCXXIIIespecialmenteMDXCIIIInaviosDCCCLXXXVIIIRey de Inglaterra

This code includes the following representation of numbers, as mentioned by Bergenroth:
MMMCCCC (read MMCCCC) -- 1000

Puebla's Great Roman Numeral Code was also used in:

Ferdinand and Isabella to Puebla, 27 April 1496 (deciphered on separate sheets) (PARES) ; an enclosed note is in what I call Puebla's Letter Code and Puebla's Second Cipher below, which Bergenroth described as a "very complicated cipher" (Bergenroth p.98-99)

Probably, the roman numerals used in the following are also elements of Puebla's Great Roman Numeral Code:

Isabella to Puebla, 6 July 1496 (PARES)

Ferdinand and Isabella to Puebla, 8 July 1496 (PARES)

Another undated letter (Simancas, PTR,LEG,52,DOC.124, PARES) from 1495

Another undated letter (Simancas, PTR,LEG,52,DOC.47, PARES) from 1496

Puebla to Almazan, 7 September 1507 (PARES) ("Rey de Inglaterra" matches)

Puebla to Ferdinand, 7 September 1507 (PARES) ("Rey de Inglaterra" matches)

Puebla's First Cipher (Bergenroth/Puebla-6)

Besides Puebla's Great Roman numeral code, words and names not defined were enciphered letter by letter according to a substitution table (called Puebla's First Cipher herein just for convenience (Although there is "Puebla's 1488 Cipher" above, it may be the first in Puebla's second mission in England.)) as follows. It is given as no.6 in Bergenroth report. The following is a reconstruction I made before I found it.

This cipher is used in the following letters.

Isabella to Puebla, 18 August 1496 (PARES) (Bergenroth p.114-119)

Isabella to Puebla, 22 August 1496 (PARES) (deciphered on separate sheets) (Bergenroth p.120-121)

Isabella to Puebla, 15 September 1496 (PARES) (Bergenroth p.125-128)

Ferdinand and Isabella to Puebla, 10 January 1497 (PARES) (Bergenroth p.131-136)

Puebla to Ferdinand and Isabella, 15 June 1498 (PARES) (Bergenroth p.151-152)

Puebla to Ferdinand and Isabella, July 1498 (PARES)

Puebla to Ferdinand and Isabella, 23 October 1504 (deciphered on separate sheets) (PARES)

Puebla to Ferdinand and Isabella, 5 December 1504 (PARES)

Puebla to Ferdinand and Isabella, 5 December 1504 (PARES)

Puebla to Almazan, 21 April 1506 (PARES)

Puebla to Ferdinand, 15 April 1507 (PARES)

Puebla's Second Cipher and Bergenroth/Puebla-8

Puebla also used what I call Puebla's Second Cipher. It is similar to what Bergenroth recorded as no.8 (there is no no.7), but they are not the same.

Puebla's Letter Code

Puebla's Second Cipher was often used with what I call Puebla's Letter Code. It is similar to Bergenroth/Puebla-3 above, but they may not be the same.

bescartacnx?ellasfavnohepRey de Francialastres
bazcasadecfechofevnoshep/hopRey de Inglaterrelivino
copde la

Letter codes from this period have elements consisting of two to four letters, which usually form a pronounceable monosyllable. The elements of this particular letter code begin with either b-, c-, d-, f-, g-, h-, or l-. As can be seen from this example, the elements do not span the full range of aaa-zzz. The range of the first consonants may give a first clue to identify the letter code used.

Puebla's Second Cipher and Puebla's Letter Code were already used in a note enclosed in a letter to him dated 27 April 1496 (mentioned above). They were also used in the following letters.

Puebla to Ferdinand and Isabella, 25 September 1498 (PARES) (Puebla's Second Cipher is used with what seems to be Roman Numeral Code.)

Ferdinand and Isabella to Puebla, 12 March 1499 (PARES)

Ferdinand and Isabella to Puebla, 13 August 1500 (PARES)

Ferdinand and Isabella to Puebla, 26 August 1500 (PARES) (deciphered on separate sheets) (mainly used in the reconstruction); (PARES)

Ferdinand to Puebla (fragment), 1500-1516 (Simancas, PTR,LEG,52,DOC.122, PARES).

Ferdinand and Isabella to Puebla, 3 October 1500 (PARES)

Ferdinand and Isabella to Puebla, 1500 (PARES)

Isabella to Puebla, April 1503 (PARES)

Ferdinand to Puebla, 1505 (PARES) (Puebla's Second Cipher is used with what seems to be Roman Numeral Code.)

Ferdinand and Isabella to Puebla, 29 July 1501 (PARES) (deciphered on separate sheets)

Ferdinand and Isabella to Puebla, 18 July 1502 (PARES)

In the following, Puebla's Letter Code is used with Puebla's First Cipher.

Isabella to Puebla, 10 August 1502 (PARES) (deciphered on separate sheets)

Generic Features

Nulls (Signs without Meaning)

Nulls, that is, signs without meaning, were interspersed in the ciphertext. Nulls may be some symbols similar to those representing letters or monosyllables. In some cases, nulls were words in plain writing such as "Semper ille Cesar" or "Je vous prie" or any other words or phrases of any other language but generally different from the language in which the letter itself was written. (Bergenroth p.cxxxviii)

Use of Apparently Ordinary Words

Ordinary words of some language were not only used for nulls. In a cipher of Don Pedro de Ayala, "etiam" represented "ll" and "malus" represented "rr". (Bergenroth p.cxl)

Examples of Mixed Use

Different systems may be used in combination to represent even one word. For example, "DCCCCLXVIIII le N o γ malus ζ" represents a word "enviando" (sending): DCCCCLXVIIII(en) le(vi) N(a) o(n) γ(d) malus(-) ζ(o) (Bergenroth p.cxxxviii). In this example, a Roman numeral, a monosyllabic code, symbols (in this case approximated by Latin and Greek characters for typographical reasons) and a null are all used to represent one word.

The following example Bergenroth used in explaining his feat of deciphering is probably an actual instance: "Cox Ω MDCIX Δ" where "cox" represents "Po", Ω represents "d", MDCIX represents "rey" (king), and Δ represents "s", all amounting to one word "podreys" (you will be able). (Bergenroth p.cxliv)

Note on Representation of Numbers

Even if symbols for numbers are defined, numbers might also be spelled letter by letter by using symbols representing letters of the alphabet.

In addition to these, Bergenroth observes letters of the Latin alphabet may represent numbers. For example, "i" represents "1"; "y", "u", "n" represents "2"; and "m" represents "3". It is only the number of vertical strokes that counts. Thus, "y m" represents "5" (i.e., 2+3). Ordinary Roman numerals such as "x" (10), "L" (50), and "C" (100) were also used. (Bergenroth p.cxxxix) To some degree, the same can be said in near-contemporary French handwriting of Roman numerals (see examples like "y" "nn" etc. in another article).

Codes/Ciphers with Other Ambassadors in England

Change of Ciphers

Letters of Almazan often told an ambassador that he had changed the cipher and the old one was no longer to be used (Bergenroth p.cxxxix), though few of such communications are calendared. In July 1498, the Knight Commander Sanchez de Londoño visited England on his way to his embassy in Flanders (Bergenroth p.xx-xxi). It appears he brought a fresh cipher for Puebla.

Has received two bundles of papers, amongst which is a key to cipher, and two letters of ....
Puebla to Ferdinand and Isabella, 15 July 1498 (Bergenroth p.153)

Mattingly says Puebla held two ciphers of his own, and one in common with the Netherlands embassy between 1496 and 1507.)

Ciphers for Lodoño and the Subprior of Santa Cruz

Bergenroth's report in PRO 31/11/11 includes a substitution alphabet for the Knight Commander Lodoño and the Subprior of Santa Cruz, which is accompanied by code elements such as hatz=Archiduque, gav=Rey de Romano, giv=Rey Catholico, gey=Rey de Inglat. gay=Reyna de Inglat.

In 1498, Lodoño and the Subprior were sent as ambassadors to Flanders. On their way to their embassy, they dropped in on England to investigate Puebla's conduct (Bergenroth p.xx-xxi). Puebla acted as if he were a foreign minister for Henry VII rather than an ambassador of Spain, though he had to be retained in his position because his connection with the English court was so convenient that noone could replace him. The Catholic Monarchs had to be content themselves by sending a second ambassador to keep an eye on Puebla.

(Some ciphered letters of Londoño and his colleague, Sub-prior of Santa Cruz, are calendared. Bergenroth p.182-183, p.199-202, and Supplement p.54.)

De Ayala's Ciphers

At the English court, there was a rival ambassador for Puebla: Don Pedro de Ayala. His several cipher letters of 1499 and 1500 (Bergenroth p.205, 216, 217, 218) and one in 1501 (Supplement, p.1) are calendared.

Bergenroth's report in PRO 31/11/11 includes a substitution alphabet for Ayala, which is accompanied by code elements such as nib=Rey de Escosia, pog=yo, pu=Vuestras Altezas

Estrada's Ciphers (1502-1504)

Catherine of Aragon married Prince Arthur in 1501 but Arthur suddenly died in 1502. Ferdinand and Isabella sent the Duke of Estrada as an ambassador, who was empowered to arrange a marriage between Catherine and the new Prince of Wales, later Henry VIII.

One of Estrada's ciphers is as follows.

cab asy
cev/civ como
cuv cosa
gam despues
gep/gup de
gvp del
gnp de lo/de la
goq dotor
gey el
gix/gvx en
gur embaxador
lam habiendo
lol/lil habe
lex la
luv los
lov lo
liv luego
mag para
mam nuestra
med mejor
mens ser
mod manera
moh nos
mos querriamos
muh negocios
mul nuestro
muns la princesa (de gales)
nyz por
peb todo
pij vimos
pul vos
ra que
raf rey
ru qual
ruq mucho

This was used in the following letters (called Estrada's Cipher herein):

Ferdinand and Isabella to Estrada, 14 June 1502 (PARES) (deciphered on a separate sheet)

Ferdinand and Isabella to Estrada, 16 June 1502 (PARES)

Isabella to Estrada, 12 July 1502 (PARES)

Isabella to Estrada, 18 July 1502 (PARES)

Ferdinand and Isabella to Estrada, 18 July 1502 (PARES)

Isabella to Estrada, August 1502 (PARES)

Isabella to Estrada, 16 June 1502 (PARES)

Ferdinand and Isabella to Estrada, 10 August 1502 (PARES)

Ferdinand to Estrada, 1 September 1502 (PARES) (deciphered on separate sheets)

Ferdinand to Estrada, 1 September 1502 (PARES)

Ferdinand and Isabella to Estrada, 13 December 1502 (PARES)

Isabella to Estrada, 12 April 1503 (PARES)

Isabella to Estrada, 4 May 1503 (PARES)

Ferdinand to Estrada, 24 September 1503 (PARES) (deciphered on separate sheets)

Isabella to Estrada, 3 October 1503 (PARES)

Isabella to Estrada, 3 October 1503 (PARES)

Ferdinand and Isabella to Estrada, 24 January 1504 (PARES)

Ferdinand and Isabella to Estrada, 24 January 1504 (PARES)

Ferdinand and Isabella to Estrada, 26 June 1504 (PARES) (deciphered on separate sheets) (mainly used in the reconstruction)

The following letter from Isabella is in the Ferdinand/Isabella Cipher above. (On the first few lines, one can read words such as "passado", "causa alguna para ellos", "justificacion", "los medios", "ha enbiado", "la mayor parte a la de Rosellon y a la otra frontera de Fuenterabia para nos ...") It is yet to be found out why it employed a cipher different from the one used in the two other letters (see above) of the same date ("tres de octubre de Diii") from the Queen.

Isabella to Estrada, [3 October] 1503 (PARES (Simancas, PTR,LEG,53,DOC.69))

Bergenroth says the cipher used in a short letter from Isabella to Estrada, of 20 August 1503, was not used in other letters extant and was the only cipher he could not decipher (p.309, xii). It would be worth trying this key.

Reversion to Simplicity (after 1504)

Spanish cipher had developed into so complicated a system that some of the deciphered despatches have marginal notes such as "Nonsense", "Impossible", "Cannot be understood," or "Order the ambassador to send another despatch." (Apparently, these remarks are not calendared.) After the death of Queen Isabella in 1504, it was found necessary to return to a simpler cipher (Bergenroth p.xii).

Cipher Communication between Ferdinand and Catherine of Aragon

Catherine of Aragon, who had been only a girl when she came to England as a bride for Prince Arthur, had to fend for herself for years and was accredited as an official ambassador to negotiate with the English court. She learned ciphering in 1507. After she married Henry VIII, Ferdinand relied on cipher correspondence with Catherine in communicating sensitive matters with his son-in-law. (See another article.)

Codes/Ciphes with Ambassadors in Italy and the Great Captain

Ferdinand's Cipher with Ambassador in Naples (1495-1497)

Parisi (2004) deals with cipher correspondence in 1495-1498 between King Ferdinand and Juan Escrivà Ram (Real Academia de la Historia), Spanish ambassador in Naples. It describes an achievement from the author's cryptanalysis based on ten cryptograms. It lists two ciphers, both consisting of monosyllabic codes (nomenclator) and a symbol alphabet.

Some examples of the monosyllabic code elements (two or three letters) of the first of those two ciphers are as follows (see Parisi(2004) for more). The first letter ranges p-, q-, r-, s-, t-, v-, x-.

xnb se
xob seran
xub ha
xec siendo
xud en mucho servicio
xie socorro
xne se
xuf [eso]
xag me
xeg tan
xah toda
xeh todas
xih todo
xoh todos
xil terra
xin Venecia
xom trenta
xon venecianos
xer [vuestras altezas]
xas acerca
xus vimos
xit una
xav [napolitanos]
xnx las
xay vos
xnz ahora
xuz ayer

The paper also prints many images of the original cipher letters: two pages of 11 May 1495 (Cipher No.1); a page of 26 June 1495 (Cipher No.1); a page of 4 July 1497 (Cipher No.1) are between King Ferdinand and ambassador Juan Escrivà Ram.

The same cipher is also used in a letter from "Frederic III" (Frederick I?), King of Naples, to Ferdinand and Isabella, San Germano, 11 January 1497 in Italian, partly in cipher, not deciphered (BnF Espagnol 318 (Gallica), ff.5-6, no.5; p.34 in pdf).

Ferdinand's Cipher with Ambassador in Rome (1498) and the Great Captain (ca.1496)

A letter of six pages of 31 August 1498 from Kind Ferdinand to Garcilaso de la Vega, ambassador in Rome, reproduced in Parisi (2004), employs Cipher No.2 identified by him. It appears there are not many monosyllabic code elements, which begin with a-, b-, c-, i-, or n-.

(The ten lines at the end of the above letter of 31 August 1498 in Parisi (2004), p.115, in a different cipher, are left undeciphered by Parisi.)

The same cipher appears to be used in a fragment of a letter in cipher sent around 1496 by Gonzalo Fernández de Córdoba [Gonzalve de Cordoue], known as the Great Captain (Gran Capitan) (Wikipedia). The fragment is presented in Arturo Quirantes' blog. One can read some words on the first line ("de toda la provancia").

Ferdinand/Isabella's Cipher (ca.1500-1502)

Galende Diaz (1994) prints "Cifra general de los Reyes Católicos" as Appendix 1. The nomenclature includes "Fija del Rey de Inglaterra ...yic" (?Margaret Tudor, who married the Scottish King in 1503), "Fija del Rey de Napoles ... yoc" (?Charlotte of Naples, whose father lost crown in 1501 and died 1504), "Infante doña Maria ... yos" (Wikipedia), who married the King of Portual in 1500, "Infante doña Catalina ... yus" (Catherine of Aragon). The monosyllabic code elements (two to four letters) range v-, x-, y-, z-, b-, c-.

Several letters in this cipher are found. The correspondents include the Great Captain and Ambassador Estrada.

A facsimile of a two-page letter from Ferdinand to the Great Captain, dated 16 August 1502, is printed in Speziali (1955). In this letter, a symbol alphabet, monosyllabic codes, and nulls (one symbol and Latin words "nemo" and "animabus") are used.

The following is my reconstruction of the symbol alphabet before I was aware of Galende Diaz (1994). (Some variant styles are included for reference's sake.)

Some examples of the monosyllabic codes are as follows.

xak ducado
xik dos
xap da, d-
xnp de
xop Dio
xaq del
xeq de lo
xiq de la
xnq dello
xar despues
xix el
xox ello-s
xiy es
xny en
xez esto
xiz esta
xoz dich-
ca Venecia
cn venido
ceb va
cnc ver
cad visto
cif vos
cog ya
cng yo

The Great Captain used this cipher in his letter to Lorenzo Suarez as early as 17 August 1500 (BnF Espagnol 318 (Gallica) f.116, no.92; p.442 of pdf), undeciphered.

Another Cipher between Ferdinand and the Great Captain (May 1502, April 1506)

In 2018, another cipher used in letters from Ferdinand to the Great Captain (27 May 1502, 14 April 1506) was identified by CNI (the National Intelligence Center of Spain) (ABC; El Mundo; Jesus Garcia Calero and Juan Fernandez-Miranda, "El CNI descifra uno de los grandes misterios de la historia de España" (1, 2)). (I thank Sergio Miguel for letting me know of this news.)

The decipherment of a few sentences on the manuscript led to the discovery of the 88 cipher symbols and 237 letter-combination codes. In one letter, the King reproached the general for his contacting the King of the Romans (Wikipedia) without his sanction (see ABC2 for more).

Arturo Quirantes noticed the cipher is the same as one discovered by Bergenroth in the 19th century (his blog). Although there are symbols that do not match, it is understandable that both versions, being reconstructions, are incomplete.

According to his appraisal of the cipher in historical context, this was the first Spanish cipher to employ a cancellation sign. In addition, the nomenclature introduced some irregularity in the arrangement, though it is not a full two-part code.


Cipher (ca.1506) broken by Luis de la Cerda in 1599

The following is a cipher used in a letter, apparently concerning Archduke Philip's second visit to Spain in 1506, preserved in BNE Ms.994, f.190 (the image is licensed under CC-BY-NC-SA). It was broken by Luis de la Cerda in 1599 (see another article).

Ciphers between the Catholic King and Jeronimo Vich, Ambassador in Rome (1508-1512)

A cipher used between King Ferdinand and Jeronimo Vich (Wikipedia), Spanish ambassador in Rome, can be reconstructed from the King's letter of 30 September 1508 about the negotiations with the Holy Roman Emperor.

The following monosyllabic codes are identified.

agora --- gik
al --- plor+
alguno --- gil
alla --- gue
bar --- gih
bolona --- gog
carta --- goy
como --- dai
con --- dih
confederacion --- fIr+
contra --- doh
cosa --- die
de --- diz
del --- fic
dela --- fuc
el --- faR
ellas --- foL
en --- dav?
en --- fan
era --- fnn
es --- fem
esta --- fun
esto --- fen
exercito --- fiy
febrero --- fib
frere --- fic
guerra --- hib
ha --- heh
la --- hor
lo --- has
mandamos --- meh
mavera? --- mef
me --- flar+
mo --- nyR
no --- nnk
nos --- mok
n[uest]ra --- nym
n[uest]ro --- mem
orden? --- meq
otra --- meq
para --- ref
papa --- nye
porque --- rif
que --- pef
rey --- pio?
se --- Seh
sera --- sod
si --- pov
su --- pax
toda --- Sel
todo --- Sal
vittoria --- siq
v[uest]ra --- suv
ya --- Sig?
yo --- Soy

The cipher is used in the following letters.

Ferdinand to Vich, 30 September 1508 (PARES) (used in the reconstruction)

Ferdinand to Vich, 13 May 1510 (PARES)

Ferdinand to Vich, 22 May 1510 (PARES)

Ferdinand to Vich, 4 April 1511 (PARES), undeciphered

Ferdinand to Vich, 5 July 1511 (PARES), undeciphered

Ferdinand to Vich, 1 March 1512 (PARES) *A greater variety of symbols are observed (used in supplementing the reconstruction)

Ferdinand to Vich, 5 June 1512 (PARES), undeciphered

Ferdinand to Vich, 1 September 1512 (PARES)

(The reconstruction of the cipher was not as straightforward as it should have been. It was obvious that the first symbol "faR" represent "el" in the plaintext (it did not seem to be a null from its repeated occurrences) but the identification was not confirmed by subsequent occurrences of "el" in the plaintext. The clue was found near the end of the ciphertext, where the pattern "heh * * heh" was considered to represent "a syllable + two letters + the same syllable." Looking for this pattern in the decipherment, "ha-r-a-ha" was found just about the right place. After this, there was no real difficulty in the reconstruction.)

The following letter from 1515 appears to use a different cipher.

Ferdinand to Vich, 26 October 1515 (PARES), undeciphered

A Cipher between Charles I and Jeronimo de Vich (1519)

A cipher between Charles I of Spain (soon to be elected Emperor Charles V) and Jeronimo de Vich can be reconstructed from Charles' letter to Vich of 30 January 1519 preserved in the Spanish archives (PARES). It is similar to the one used with King Ferdinand.

The following monosyllabic codes are identified.

ala --- xur
alamana --- xaz
amigo --- xas
carta --- tof
con --- tor
como --- tis
de --- sim
dela --- seo
el --- sex
emperador --- sir
en --- sey
esta --- sez
Inglaterra --- ree
grande --- roq
importa --- paf
lega --- pop
legado --- pir
llegare --- paq
la --- poq
lo --- piq
mal --- nub
muy --- nol
mucho --- nif
natural --- noq
no --- nen
nos --- nin
nuestro --- nuo
nuestra --- noo
otra --- niv
papa --- mod
para --- mio
parte --- meq
poder --- man
por --- meo
principe --- mud
provecho --- mee
puede --- mum
que --- mox
su --- cix
tiene --- ben
todo --- bol

Unidentified Ciphers

BnF Espagnol 318 (Gallica) includes, in addition to the two mentioned above, the following letters in cipher, undeciphered.

f.122, no.95 A letter of 8 January 1497

f.120-121, no.94 Viceroy of Sicily to Ferdinand, 27 April 1503

f.118, no.93 (p.448 of pdf) Lorenzo Suarez to Ferdinand and Isabella, Venice, 24 February 1504

In 2022, Geoge Lasry provided me with his "approximate" solution for f.122 (see another article).

Ferdinand's Last Cipher and the Next Reign

Ferdinand the Catholic died in 1516. Shortly before his death, he updated the cipher for Bernardino De Mesa, ambassador in England (1515-1518, 1519-1523).

And since the cipher in which you are now writing, although reasonable, is not very safe, and might be deciphered if several letters in it were intercepted, we charge you, for the greater security of anything you may have to write in cipher henceforward, to make use of the cipher alphabet recently sent you from Spain by his late Catholic majesty.
Charles I, King of Castile, to Bernardino de Mesa, 15 July 1516, (Further Supplement)

The basic form of cipher consisting of symbols and monosyllabic codes was inherited into the next reign.


Several keys identified by Bergenroth as well as his reporting letter of 4 January 1861 (called "Bergenroth's report" herein) are preserved in PRO 31/11/11 in the UK National Archives (see another article). The keys preserved in the General Archive of Simancas in Spain are catalogued in J.G.Carmona (1894), Tratado de criptografia con aplicacion especial al Ejercito (p.181-192).

Some Ciphers Preserved in the Archives

Galende Diaz (1994) describes a file of ciphers in 25 folios preserved in the archives (B.R.A.H. [Biblioteca de la Real Academia de la Historia], sign.9/15) and reproduces some in the appendix. In the following, the numbering and some of the annotations are mine.

no.1 (ff.1-6) Cipher of the viceroy

no.2 (ff.7-9; Appendix 1) "Cifra general de los Reyes Católicos." This is described as Ferdinand/Isabella's Cipher (ca.1500-1502) above. The monosyllabic code elements (two or three letters) range v-, x-, y-, z-, b-, c-.

no.3 (ff.11-14) Cipher between Alonso de Silva and Garcilaso de la Vega. The latter was ambassador in Rome in 1496-1499 (Rosa Helena Chinchilla (1996) "Garcilaso de la Vega Senior, Patron of Humanists in Rome: Classical Myths and the New Nation" (Bulletin of Hispanic Studies)) and the father of a poet (Wikipedia)

no.4 (f.15) with Don Diego de Muros, Bishop of Oviedo (1512-1523) (Wikipedia)

no.5 (f.16, Appendix 2) Cifra with fray Juan de Mauleón, whom the French king sent as ambassador to King Ferdinand to discuss devolution of Roussillon [Rosellón]: the small nomenclature includes signs for "Principe de Spanya" (?John, the King's only son, who died in 1497) and "Infanta dona Juana" (Joanna the Mad, who married Emperor Maximilian's son in 1496). Twenty symbols are provided for names.

no.6 (f.18, Appendix 3) Cipher of Don Juan Manuel (ambassador at the court of Emperor Maximilian) with his wife. When Queen Isabella died in 1504 and named Ferdinand regent of Castile, Juan Manuel was among the dissasisfied and favored Maximilian's son Philip, married to Infanta Juana, to take up the regency (Prescott, History of the Reign of Ferdinand and Isabella, vol.3 (1838), p.279). About thirty monosyllabic code elements are provided for short words and some words. The first letter varies.

no.7 (f.19, Appendix 4) Cipher of Don Juan Manuel and the Marquis of Villena (Diego Lopez de Pacheco, who was among the most prominent of those dissatisfied with Ferdinand's regency (Prescott, p.278).) Six monosyllabic code elements are provided. The first letter varies (daz, da, dof, bis, ves, qus).

no.8 (f.21) Cipher with Archbishop of Monreale [Montesregalis] (?Juan Castellar y de Borja, who left Rome to visit King Ferdinand in 1504)

no.9 (f.22, Appendix 5) Cipher with Don Juan Ruiz de Medina (Wikipedia), ambassador in Rome. The monosyllabic code elements (two or three letters) ranges b- and l-.

no.10 (f.23, Appendix 6) Cipher with Alonso de Aragon (Wikipedia), an illegitimate son of King Ferdinand. The code portion consists of two to six letters and graphic symbols.

no.11 (f.24) Cipher "entre reyes" (Galende Diaz considers it was for members of the royal family.)

no.12 (f.25, Appendix 7) Cipher between Juan Claros de Guzmán, Duke of Medina Sidonia and Medina de las Torres (Galende Diaz points out that the only Juan Claros with both of these titles is the the 11th Duke of Medina Sidonia (1642-1713)), and Diego Alfonso de Páramo. This is a simple monoalphabetic substitution cipher with Arabic figures, with a few three-digit code elements. This (as well as possibly some others of the above) may be an excerpt rather than the original cipher.


Bergenroth, G.A. (ed.) (1862), Calendar of State Papers, Spain (Google: Vol. 1, Vol. 2, Supplement, Further Supplement; British History Online), in particular, "Remarks on the Ciphered Despatches in the Archives at Simancas", Vol. 1, p.cxxxvii *The copy at Google lacks pages after p.464 (7 August 1508). (Vol. 1 is simply referred to as "Bergenroth" hereinabove.)

Cartwright, William Cornwallis (1870), Gustave Bergenroth: a memorial sketch (Internet Archive, Google) This reprints "Remarks on the Ciphered Despatches in the Archives at Simancas" in the appendix. (Simply "memorial" hereinabove.)

Ivan Parisi (2004), 'La Correspondencia Cifrada entre el Rey Fernando el Católico y el Embajador Joan Escriv è de Romaní i Ram,' Pedralbes, 24, pp.55-116 (PDF)

Pierre Speziali (1955), 'Aspects de la Cryptographie au XVIe Siecle', Bibliotheque d'Humanisme et Renaissance, Tome XVII

Juan Carlos Galende Díaz (1994), 'La escritura cifrada durante el reinado de los Reyes Catolicos y Carlos V', CEMYCYTH [Cuadernos de estudios medievales y ciencias y tecnicas historiograficas], XVIII-XIX 1993-1994, 159-178 (pdf)

Juan Carlos Galende Díaz (2006), 'Basic Concepts of the Cryptology: The Manuscript of the Biblioteca Nacional,' Documenta & Instrumenta, 4, pp.47-59 (PDF) This appears to deal with classic codebreaking techniques for Spanish and reproduces no.7 of Galende Diaz (1994).

Garrett Mattingly (1955), Renaissance Diplomacy (Internet Archive) p.274 n.137

Ulick Ralph Burke, History of Spain from the Earliest Times to the Death of Ferdinand the Catholic 2nd ed. Vol 2 (1900) (Internet Archive)

Related Articles:

S. Tomokiyo, Spanish Ciphers before Accession of King Ferdinand: 1470-1479 (

S. Tomokiyo, Ciphers during the Reign of Emperor Charles V

©2011 S.Tomokiyo
First posted on 5 February 2011. Substantially corrected on 5 January 2019. Reorganized on 24 February 2019. Last modified on 29 May 2022.
Cryptiana: Articles on Historical Cryptography
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