French ciphers during the Reigns of Charles IX and Henry III

Ciphers during the reigns of Charles IX (1560-1574) and Henry III (1574-1589) are presented. See also my related articles:

"Catalogue of Ciphers (Mainly Related to Duke of Nevers) in BnF fr.3995" and

"A List of Cipher Materials in Mémoires de la Ligue in the French Archives"

(By the way, Henry III was called "Vilain Herodes" (an anagram of "Henri de Valois") by the preacher Jean Guincestre after his assassination of the Duke of Guise in 1588.)

Table of Contents:

Ciphers of Charles IX and Queen Mother, Catherine de Medici (Rennes, Villeparisis, Mans, Foix, Grandchamp, Acqs, Ferrals, Hurault)

Henry III's Cipher with Ambassadors (Vivonne in Spain, Longlee, Foix, d'Este, Vivonne in Rome, Maisse in Venice, Germigny, Germigny-Maisse, Savary)

Duke of Anjou's Cipher

Agents' Ciphers?

BnF fr.15560-15574 (15560, 15561, 15562, 15563, 15564, 15565, 15566, 15567 (Matignon-1, Matignon1, Aubeterre, f113, Hautefort, Maygnieulx), 15568, 15569 (Matignon2), 15570, 15571 (Chasteauneuf, f184), 15572 (Mayenne1, Camus, Malycorne, Matignon3, Mayenne2, MatignonTuple, StLuc, Biron), 15573, 15574)

References to Cipher in the Correspondence of Catherine de Medici

References for Background

Ciphers of Charles IX and Queen Mother, Catherine de Medici

(The King and Queen Mother used the same ciphers as far as the specimens here are concerned.)

Bishop of Rennes (1561-1564)

BnF Colbert 390 (Gallica) contains many letters partially in cipher addressed to Bernardin Bochetel, Bishop of Rennes (Wikipedia), ambassador to the Emperor. Most are from Catherine de Medici, but one (p.229) is from Charles IX (not that they did the ciphering themselves; the letters are undersigned by secretary of state, L'Aubespine (Wikipedia) or Bourdin (Wikipedia)). (Most are deciphered on separate sheets or in the margin. The deciphering of p.117 starts on the verso (p.120) of the next leaf. The deciphering of p.189 is misplaced on p.199. The deciphering of p.317 is found on p.313. P.217 is interesting for the trembling signature of Catherine. P.139 (see below) and p.357 are not deciphered.) The same cipher is also used in an undeciphered letter from Bourdin to the Bishop of Rennes in BnF Colbert 392 (Gallica), p.231 (p.114 of pdf).

The cipher can be reconstructed as follows.

Some of the letters in BnF Colbert 390 use many nulls, not only at the beginning and the end of the ciphertext, but also between words and even within words. The undeciphered note on p.139 (p.72 of pdf) is one such example. (Below the ciphertext is a note "Deschiffrez vous mesmes ....")

Bishop of Rennes and Cardinal de Lorraine (1563)

A cipher used in a letter of 1563 from Charles, Cardinal of Lorraine to the Bishop of Rennes (BnF Colbert 392 (Gallica), p.27 (p.18 of pdf)) is reconstructed as follows.

Villeparisis, Resident in Rome (1564)

BnF fr.16039 (Gallica) contains cipher letters from Rome to Charles IX and Queen Mother, Catherine de Medici.

A letter (1564) (f.17) of Henri Cleutin [or Clutin], Seigneur de Villeparisis, (Wikipedia), a resident in Rome in 1564-1566, used the following cipher.

Bishop of Mans, Ambassador in Rome (1569)

Letters (1569) (BnF fr.16039 (Gallica), f.181, f.203, and probably also f.173) of Charles d'Angennes de Rambouillet, Bishop of Mans, (Wikipedia), ambassador in Rome from 1568, used the following cipher.

Paul de Foix, Ambassador in England (1565)

Paul de Foix (Wikipedia) was ambassador in England. BnF fr.15971 (Gallica) contains his letters dated 11 October 1565 partly in cipher to the King and Queen Mother (f.21, f.26). The cipher can be reconstructed as follows. Unlike other French ciphers at the time, there is a symbol for the letter "k", used in spelling English names such as Throckmorton and Norfolk.

Philibert du Croc, Ambassador in Scotland (1565-1567, 1572)

Paul Destray (1924), Un diplomate français du XVIe siècle: Philibert du Croc (Gallica) presents the following.

Catherine de Medicis to Philibert du Croc (1567)

I learned of a letter dated 27 April 1567 partly in cipher from Catherine de Medicis (undersigned by L'Aubespine) to Philibert du Croc reproduced in Destray (1924) (p.53 and the leaf next to p.56) at Cipherbrain. The clear text preceding the ciphertext ("jay recu du sr x3 lettres en datte") may suggest the ciphertext begins with "du."

Charles IX to Philibert du Croc

A letter in cipher from Charles IX to Philibert du Croc is reproduced in Destray (1924) (p.80 and the next leaf). Although the letter is not dated, the endorsement indicates Philibert du Croc was then ambassador in Scotland.

In 2022, this was solved by George Lasry (see another article).

La Forest-du Croc Cipher (1567)

A cipher between Bochetel de La Forest (probably Jacques, ambassador in England) and Philibert du Croc (1567) is reproduced (leaf next to p.32; p.30).

This employs ordinary words for names: "bien" (La Reyne dangre), "bonte" (La Reyne decosse), "sans ...[?]" (Angloys), "dain[?]" (Escossois), "quant" (Irlandoys), "chacun" (Irlande), "veult" (Le duc do...[?]), "bon" (Le Roy), "Joyeuse" (france[?]), "gaillardz" (francoys), "bastardz[?]" (flandres).

A Cipher Used in Reporting a Letter between Throckmorton and Chatillon (1568)

BnF fr.15971, f.155, wholly in cipher, deciphered on f.156, is annotated "12 Septemb. 1568", "lettre de Tomarton au Card. de Chastillon". Actually, the title line in cipher reads "lectre de Trocmarton a Monsieur le Cardinal de Chastillon". That is, the cipher is not one used between Throckmorton and Cardinal de Châtillon (Wikipedia). The letter was enciphered by someone who reported it. The cipher can be reconstructed as follows.

Châtillon was a Protestant. He fought at the Battle Saint-Denis in 1567 and fled to England in 1568. In September 1568, he wrote letters to the King and Queen Mother begging their favour, while he also wrote to Queen Elizateth to seek asylum in England.

Grandchamp, Ambassador in Constantinople (1569-1571)

BnF fr.16142 (Gallica) contains letters in cipher (1569) from Constantinople to Charles IX or Queen Mother, Catherine de Medici (f.3, f.15, f.17, f.19, f.27). Some are deciphered in the margin, on separate pages, or between the lines. Others are not deciphered, of which at least some are deciphered by M. de Fréville in Négociations de la France dans le Levant (1853), p.80 (Internet Archive).

These are from Guillaume de Grandchamp de Grantrie (Wikipedia), ambassador in Constantinople from 1566 to 1571. La Tricquerie, charge-d'affaires, used the same cipher in 1570-1571 (f.50, f.54, f.62).

It appears at one time Grandchamp had to discard his cipher.

d'aultant que quant Jhean-Batiste et le sr de la Tricquerie furent prins, je rompis mon chiffre, et que je n'ay sceu trouver dedans les pappiers de mon secrettaire le double, j'ay esté contrainct d'advertir M. de Fois bien amplement pource que j'ay son chiffre, affin qu'il rende plus ample conte à V.M. de tout ce qui se passe, comme il m'asseure qu'il fera.
Grandchamps to Charles IX, 3 October 1569 (Negotiations, p.95)

Bishop of Acqs, Ambassador in Constantinople (1571-1574)

François Noailles, Bishop of Dax (or Acqs) (Wikipedia), was ambassador in Constantinople from 1571.

His letter in September 1571 used the following cipher (BnF fr.16142, f.92).

His many letters from December 1571 to July 1574 to the King, Queen Mother, and Duke of Anjou used the following cipher (BnF fr.16142, f.109-f.253). The same cipher was also used in 1574-1576 by Gilles de Noailles (Wikipedia), François Noailles' brother and successor, who was sent by Henry III, who succeeded Charles IX in May 1574 (BnF fr.16142, f.254-275).

Sieur de Ferrals, Ambassador in Rome (1572-1574)

BnF fr.16040 (Gallica) contains many cipher letters (1572-1573) from Ferrals (François Rougier, baron de Ferrals [Ferals, Ferralz]), ambassador in Rome, to Charles IX. The same cipher is also used in Ferrals's letter to the King of 2 January 1574 (BnF fr.16041 (Gallica), f.1). The cipher can be reconstructed as follows.

Hurault, Ambassador in Venice (ca.1564?)

BnF Colbert 395 (Gllica), p.335, appears to be a letter from Jean Hurault[?] (Wikipedia). The marginal note on p.336 mentions "... chiffre: que vous dechiffrez ...", which I cannot read.

There is a plaintext on p.337, but since I could not match it with the ciphertext, I thought it is not the decipherment and posted it as undeciphered. In 2022, George Lasry solved it (see another article), which showed p.337 was indeed the corresponding plaintext.

A Letter to the King in BnF fr.3254

A letter "to the King" in BnF fr.3254 (Gallica), f.76, is almost entirely in cipher. This was brought to my attention by George Lasry, who solved it (see another article). The volume contains many letters of Charles IX or Catherine de Medicis to Matignon and others from 1570-1573 and a copy of one letter of François de Cornelian, bishop of Roddez from 1583.

Henry III's Cipher with Ambassadors

French diplomatic ciphers used with ambassadors are presented in this section.

Nicolas de Neufville, Sieur de Villeroi (1577)

A letter in cipher from Villeroi to Henry III of France was sold at an auction. It is wholly in cipher except for the complimentary ending: "Sire ie prie dieu conserver vre mté en parfaicte santé / De Bergerac ce viiie jour de sepbre 1577" and the signature "Vre très humble très obéissant & très obligé subjet & serviteur. Deneufville" in Villeroi's hand. (The date is shortly before the Treaty of Bergerac (Wikipedia) was made between the King and the Huguenot princes. Villeroi was one of the King's negotiators.)

This was solved by George Lasry in 2022 (see another article). (I had made a try by using some interlinear decipherment, but was unsuccessful (my blog).

Jean de Vivonne, Sieur de Saint-Gouard, Ambassador in Spain (1572-1582)

Jean de Vivonne, Sieur de Saint-Gouard (later marquis de Pisani), "one of France's most competent career diplomats", was ambassador in Spain in 1572-1582 (Jensen p.27).

Many letters of Vivonne to the King contain cipher paragraphs. The cipher used from April 1572 to November 1574 in BnF fr.16104 (Gallica), BnF fr.16105 (Gallica), and BnF fr.16106 (Gallica, up to f.198) use the following cipher. (That is, Henry III's succession to the French throne upon the death of his brother in May 1574 did not cause a change of cipher.)

(Here and in the following, signatures are reproduced to help identifying writers of despatches in the archives.)

Some letters use many nulls, but the nulls used at the beginning of a cipher passage are relatively apparent. For example, BnF fr.16104 f.298v has a whole line of null characters, but they look so dissimilar from the other characters and it is pretty much obvious that they are nulls.

Occasionally, decipherments in the archives are misplaced and misdated, as reported in Mousset p.xlviii. Two examples in BnF fr.16105 are as follows:

f.38 a letter partly in cipher ("10 Mars 1573")

f.41 "dechifre de la precedente" ("10 Mars 1753") ... this actually corresponds to f.43

f.43 a letter mostly in cipher ("13 Mars 1573")

f.45 "dechifre de la precedente" ("13 Mars 1573") ... this actually corresponds to f.38 (there appear to be textual differences; near the beginning, "desagreable" in cipher reads "mauvais" in the decipherment.)

At least from 1579 (BnF fr.16106 (Gallica) f.207 (the volume includes almost none from 1575-1578)), Vivonne used a different cipher, which he used until the end of 1582 (BnF fr.16107 (Gallica), BnF fr.16108 (Gallica)) and which he left for his successor Longlee by the King's order (Mousset p.x) (hence it is called Longlee's cipher herein and is presented below).

A passage in a letter from Pierre Dor, French consul in Lisbon (d'Ars, p.115), to Vivonne dated 10 February 1580 (BnF fr.16107 f.63) employs the following cipher.

A letter from Jean Pierre d'Abadie to Vivonne, French resident in Lisbon (Lettres de Henri III, roi de France: 8 avril 1580-31 decembre 1582 (Google)), dated 2 May 1580 (BnF fr.16107 f.225) employs the following cipher.

Pierre de Segusson, sieur de Longlée-Renault, Resident in Spain

Pierre de Segusson, sieur de Longlée-Renault was de facto ambassador in Spain (his official title was "résident permanent" (Ribera)) from 1582 to 1590. Throughout this period, he used the following cipher (called Longlee's cipher herein), which was left for him by Vivonne. (The evidence found in BnF fr.16110 is up to July 1588 (f.276) but Longlee is reported to have used the same cipher with Henry IV in 1590 (Mattingly p.215). It can be confirmed in Longlee's three letters preserved in BNE Ms.994, f.64-70, of which one is dated 1 April 1590. )

Longlee's despatches are found in BnF fr.16109 (Gallica) and BnF fr.16110 (Gallica) among others and printed in Albert Mousset (ed.), Depeches diplomatiques de M. De Longlee (1912) (Internet Archive, Google), which presents the editor's reconstruction of the cipher (p.lviii-lix). In the above image, I limited myself to only those symbols I actually came across.

A reconstruction by the contemporary Spanish codebreaker Luys Valle de La Cerda is also extant (Mousset According to Mattingly (p.215), Longlee's cipher had been broken in 1587. (In July 1587, Philip II warned Bernardino de Mendoza, his ambassador in Paris, that Longlée knew Mendoza's secret meetings with his informant (Jensen, Diplomatcy and Dogmatism p.108, 148).) It had also been broken by partisans of Henry of Navarre. M. du Pin (Jacques Lallier, Sieur du Pin, Secretary of State to the King of Navarre) wrote to Walsingham in England on 30 March/9 April 1587: "I send you the copy of a letter from the French ambassador in Spain, M. de Longlee, which has been deciphered and which I think you should see, and make what use of it you can." (CSP, Elizabeth vol.21, Part 1 (British History Online)). Although Henry of Navarre was heir presumptive, he was then at war with Henry III (the War of the Three Henrys (Wikipedia)).

Another cipher of Longlee is preserved in BnF fr.4053 (ff.99-100) but appears to have never been used (Mousset p.liii).

When Henry III was assassinated, Longlee supported the Protestant succession by Henry IV, who told him to remain at his post in November 1589. But Philip II did not recognize Henry IV and hence could not accept his ambassador. Longlee's position became difficult and he was recalled in April 1590. (Mousset p.xxviii-xxx)

Paul de Foix, ambassador in Rome

Paul de Foix (Wikipedia) was ambassador in Rome from 1579 until his death in 1584. Two letters in cipher from de Foix to the Queen (Catherine de Medici) are in BnF fr.16043 (Gallica) (f.243, 1 October 1581; f.286, 13 November 1581) and more letters in cipher to the King or the Queen in 1582-1583 are in BnF fr.16044 (Gallica, f.6, f.29, f.181, f.380v). Unlike typical French diplomatic ciphers at the time, de Foix used a numerical cipher. (Numerical ciphers are also found in the Nevers collection. See, e.g., no.63, no.64 in another article.)

Anonymous Figure Cipher (1586)

BnF Clair 357, f.167, is a letter in figure cipher dated 28 October 1586. (Though not signed, the characters affixed at the end may indicate the sender.) While about two thirds of the first page is not deciphered, the reconstructed cipher below reveals "jay reccu voz deux lettres en ung mesme temps dont jay faict comunication a ...."

Cardinal d'Este, Cardinal Protector for France in Rome

Many letters in cipher from Luigi d'Este (Cardinal d'Este, Cardinal of Ferrara) (Wikipedia) in Rome to Villeroi in 1584-1586 are in BnF fr. 16041, f.259, 264, etc. (Gallica) and BnF fr.16042 (Gallica). Being a grandson of Louis XII, Cardinal d'Este represented France in the College of Cardinals (Wikipedia, d'Ars p.160) and played a key role in the papal conclave of 1585 (Wikipedia).

The cipher can be reconstructed as follows.

Jean de Vivonne, Sieur de Saint-Gouard, Marquis of Pisany, Ambassador in Rome (1584-1589)

Vivonne was ambassador in Rome in 1584-1589, succeeding Paul de Foix, and worked with Cardinal de Joyeuse, Cardinal Protector for France (Jensen p.37, d'Ars p.152).

Vivonne used ciphers different from what he used in Spain. His letters to the King in 1585 used the cipher below. (4 June 1585 (f.50), 7 June 1585 (f.63), 16 June 1585 (f.69), 17 June 1585 (f.75), 2 July 1585 (f.93), 2 July 1585 (f.97), 17 July 1585 (f.105), 17 July 1585 (f.114), 23 July 1585 (f.121) in BNF fr.16045 (Gallica)) Some symbols look like two symbols (see those for "l", "pour", "que"). Symbols for "b" look the same as those for "c".

Vivonne's letters to the King in 1586-1587 use the following cipher. (8 September 1586 (ff.228-234), 17 September 1586 (f.240-245), 17 September 1586 (f.246-247), 4 November 1586 (ff.272-280), and 24 March 1587 (f.297-f.303) in BNF fr.16045 (Gallica))

One specimen in this cipher reads as follows (see also the image).

le ruinat de reputation et decredit avecque les princes Protestans et autres avec les quels il a ses principles inteligences et de sorte lentretenir que il voudroit retourner a ses premieres pratiques il fust sidien descheu de toute confidence des inteligences quil a a ceste heure quil luy fust impossible de sen pouvoir plus valoir que je croyois *ele asseurement que au premier soupcon que les *s auroient de luy il seroit a demy ruyne et pu tout sans nule dificultes sil les abandonoit du tout.
Vivonne to Henry III, 17 September 1586 (BnF fr.16045, f.244)
This letter is printed in Giovanni Anticona (2012-2013), "La correspondance diplomatique de Jean de Vivonne, ambassadeur a Rome" (, p.105, with an incmplete transcription of the decipherment in the margin.

Two letters of 18 June 1588 from Vivonne to the King in BNF fr.16046 (Gallica) (f.165 ff., f.179 ff.) use the following cipher.

When Henry III was assassinated in August 1589, the Marquis of Pissany had been dismissed in the midst of tensions over the Catholic League and was away from Rome (Jensen p.37, d'Ars p.308-309). Being a royalist, he immediately joined Henry IV (d'Ars p.313), who sent the marquis to Rome for negotiation on his behalf (p.317). But permanent embassy was not established in Rome until after the coronation of Henry IV (Jensen p.37).

André Hurault de Maisse, Ambassador in Venice

André Hurault, sieur de Maisse (mentioned in Wikipedia) was ambassador in Venice from 1582 to 1596, except for a brief period in 1588-1589. When he was sent to Venice in 1589, now representing Henry IV, Venice not only accepted him despite intervention of the Spanish ambassador and the papal nuncio, but also became the first Catholic state to send an ambassador to the Protestant French king. Henry IV also sent, as early as August 1590, de Maisse to the Grand Duke of Tuscany, who helped Henry IV's cause during this critical period.(Jensen p.34-36, d'Ars p.318)

BnF fr.16092 (Gallica) contains "La Clef du chiffre de Mr de Maisse Ambassadeur a Venise" (f.5). It is a numerical cipher as follows, but I have not seen its actual use.

The many letters in BnF fr.16092 from Henry III (countersigned Neufville (i.e., Villeroi) (Wikipedia)) to de Maisse in 1582-1585 employs the following cipher, which is typical of the French ciphers at the time. The same cipher is also used in many letters in 1586 to May 1587 in BnF fr.16093 (Gallica) (ff.1-159).

Jacques Germigny, Ambassador in Constantinople (1579-1585)

(Gallica: NAF 22048, NAF 22070)

NAF 22048 (NAF=bibl. nat., nouv. acq. fr.) and NAF 22070 (both concerning correspondence of Jacques de Germigny (Wikipedia), ambassador to Constantinople in 1579-1585) succeeding Gilles de Noailles contain many letters of Henry III in cipher. While the deciphering in the margin is hard to read, transcription in Lettres de Henri III helped reconstruction of the cipher. For example, the letter of f.8 in NAF 22048 (addressed to Sr de Germigny, dated 27 August 1579) is no.3480 (p.258) therein.

Ciphertext in this volume uses many nulls, even within a word.

(Unlike the above specimen, Wikipedia presents Henry III's signature in Latin.)

BnF fr.16144 (Gallica) contains many letters from Germigny to the court (f.76 ff.) as well as those of Secretary (Recveil Des Pieces Choisies (1661) p.33 (Google)) Berthier from 1585-1586 (f.3 ff.), who used the same cipher.

Germigny-Maisse Cipher (ca.1574-1589?)

NAF 22070, f.69 is an original cipher with an endorsement "Chiffre avec Monsieur de Maisse, Ambassadeur pour le Roy a Venise [signed] Germigni", that is, André Hurault de Maisse. This cipher is in the style of many court ciphers at the time.

Jacques Savary de Lanscosme, Ambassador in Constantinople (1585-1589)

Jacques Savary de Lanscosme (Wikipedia) succeeded Germigny. He used the following cipher in letters of 1588 preserved in BnF fr.16144 (Gallica), ff.75-206.

This cipher provides for a symbol to double the preceding letter.

Savary was associated with the Catholic League and did not accept Henry IV as King of France. He was imprisoned by the Ottomans and his relative, Francois Savary de Brèves (Wikipedia, Jensen p.33), who had accompanied him in 1584, as interim ambassador, and then official ambassador. (The ciphers used by Savary de Breves in the next reign are different from the above, with Arabic figures and other symbols. See another article.)


BnF fr.3323 (Gallica), f.1., contains "Chiffre avec monsieur le chancellier (?René de Birague (Wikipedia)), du XVIe de settembre 1575."

It is a substitution cipher with two or three homophone for each letter of the alphabet. Nulls as well as symbols for double letters are defined. The nomenclature assings Arabic figures 10-120 to names, locations, and some common words.

Duke of Anjou's Cipher

A cipher used in a letter of the Duke of Anjou, brother of the king, to the governor of Cambrai (January and February 1583), broken by the Spanish codebreaker Luis de la Cerda (see another article) is preserved in BNE Ms.994 (f.5-9) (the image is licensed under CC-BY-NC-SA).

Agents' Ciphers?

A Cipher used by La Boderie with his Brother (1585)

A letter partly in cipher "Du sr de la Boderie au sr de Melimont son frere", dated London, 8 October 1585, is in BnF fr.15972 f.10-12 (Gallica). La Boderie may be Antoine Le Fèvre de La Boderie (1555-1615), who served as an ambassador in England in 1606-1611, but his activities in 1585 are not found in the description of his early careers found in the preface of Ambassades de Monsieur de la Boderie en Angleterre sous le règne d'Henri IV (Google) or in the reference to him in a Wikipedia article of his brother. Moreover, his brother Melimont is not found in his genealogy.

The cipher can be reconstructed as follows.

As is often the case, the handwriting of the plaintext made the reconstruction difficult. Matching the ciphertext and plaintext at the beginning and the end came to a deadend. (Of those, at least my assignment of "si tost" near the end turned out to be correct. Vertical signs in the ciphertext often (but not always!) indicating word breaks helped alignment.)
I found "xviii" in the ciphertext and, as expected, the plaintext had its counterpart. But the words surrounding it were hardly legible. Then, I found "xx" in the ciphertext, but the counterpart was not found in the plaintext. Then, I thought "mil" (one of the few words I could recognize in the plaintext) might be preceded by "vingt", which should correspond to "xx" in the ciphertext. This revealed the signs for "m", "i", "l" (and "que" preceding "vingt"). After this initial finding, the reconstruction was only a matter of time.

A Cipher used in Memoires concerning Scotland (Undated)

Memoires in cipher, titled "Memoires concernans quelques grands d'Escosse qui se declarent pour le Roy prenans pretexte de vouloir restablir la religion en Escosse et Irlande" is in BnF fr.15972 f.40 (Gallica). The cipher can be reconstructed as follows.

Although this document is filed after a document relating to the execution of Mary, Queen of Scots in 1587, historians' help is needed to date this document. Dating is important because the extensive use of Arabic figures with diacritics is a characteristic often seen in ciphers in the reign of Henry IV.

BnF fr.15560-15574

BnF fr.15560-15574 include many letters in cipher addressed to the court of Henry III of France. Many are addressed to the King or his counsellor Villeroi (Wikipedia). While many ciphers have been reconstructed from already deciphered materials, there still remain some unidentified ciphers.

BnF fr. 15560

Apparently no cipher.

BnF fr. 15561


F.42 is a letter of 12 July 1579 from Don Juan de Borgia, Spanish ambassador at the imperial court of Maximillian II, then at Prague, to Philip II, reporting the Prince of Parma's seizure of Maastricht in June. The reconstructed cipher is given as "Cipher with Don Juan de Borgia (1579)" in another article.

BnF fr. 15562


Ff.65-66 and ff.69-70 are letters mostly in cipher. The former has some interlined text, which allowed reconstruction of the cipher. Deciphered text revealed it was information from Antwerp, dated 16 January 1580. See another article for decipherment and reconstructed cipher.

BnF fr. 15563

Apparently no cipher.

BnF fr. 15564


f.27, f.78, f.119, f.142

These are letters to Mr de Mercoeur probably from the Duke of Guise. Undeciphered. (Several ciphers related to the Duke of Guise are given in another article and one cipher used by the Duke of Mercoeur is in another article but they do not seem to match.)

In 2022, George Lasry solved it (see another article).


Undeciphered. Dated "ce xxvje juin." Endorsed "A Monseigneur / Monseigneur le Duc de Mercoeur"


This letter, addressed to Villeroi, has several lines in cipher. The reconstructed cipher is as follows. (The last line cannot be read except for the first "d.")

BnF fr. 15565


The undeciphered letters in this volume ("probablement de princes de la maison de Guise") were solved by George Lasry in 2022 (see another article). F.105 and f.122 use the same key as f.27 etc. in BnF fr.15564.

The cipher in f.7, f.62, and f.91 is solved as follows.

BnF fr. 15566



An undeciphered letter. George Lasry solved it in 2022, though the solution is preliminary because the ciphertext is too short (see another article).


A letter partially in cipher, deciphered. Uses Aubeterre's Cipher below.

BnF fr. 15567 (January to March 1584)


f.24, f.54

Uses Matignon's Cipher-1, reconstructed as below. (The last line on f.54r appears to be all nulls.) For the maréchal de Matignon, see Wikipedia.


Uses Aubeterre's Cipher (partially deciphered between lines), reconstructed as below. (This Aubeterre is probably David Bouchard d'Aubeterre mentioned in Wikipedia.)


The following can be reconstructed from interlined deciphering.

f.158, f.160, f.207

Uses Hautefort's Cipher, reconstructed as below from partial interlined deciphernig. (This Hautefort is probably Jean de Bellièvre (1524-1584) mentioned in BnF Data.)

f.162, f.194

Uses Maygnieulx's Cipher, reconstructed as below.

BnF fr. 15568



Uses Aubeterre's Cipher (see above).


Uses Matignon's Cipher-1 (see above).


Uses Hautefort's Cipher (see above).

BnF fr. 15569



A letter (April 1585) in seven pages from Matignon to Henry III. Mostly in cipher, deciphered in f.133. Uses Matignon's Cipher-2, as reconstructed below from f.131.

BnF fr. 15570



A letter (September 1585) of Matignon. Mostly in cipher, with interlined decipherment for a few portions. Deciphered in f.273.

Uses Matignon's Cipher-3 (see below).

BnF fr. 15571


Chasteauneuf's Cipher

Used in ff.34-35 (deciphered in f.36). (There seem to be more words in the deciphered text before "protestans" than in the ciphertext, even if allowing for one or two code symbols I could not identify.)

L'Aubespine-Châteauneuf or Guillaume de L'Aubespine, baron de Châteauneuf-sur-Cher was ambassador to England from 1584 to 1589 (Wikipedia).


A letter from Forget to Villeroi of 31 December 1585. Undeciphered. Uses Mayenne-Forget's Cipher 1 (see below).


Entirely in cipher, undeciphered (The digital image of BnF for this page is upside down.). Uses Matignon's Cipher-3 (see below), which allows deciphering (see the image).


A letter with many key words in cipher, with interlined decipherment. The cipher can be reconstructed as follows.

BnF fr. 15572 (January to July 1586)


Mayenne-Forget's Cipher-1

This is used among Charles of Lorraine, Duke of Mayenne (Wikipedia), Forget de Fresnes (Wikipedia), the counsellor Villeroi (Wikipedia), and King Henry III. Letters in this cipher are found in f.14 (deciphered in f.15), f.18-21 (deciphered in f.19), f.78-79 (deciphered in the margin), f.91-92 (deciphered in the margin), f.110 (undeciphered), f.123-124 (undeciphered), f.143 (undeciphered), f.150 (undeciphered), f.154 (undeciphered), f.173 (undeciphered), f.196 (undeciphered), f.201 (undeciphered), etc.

Numerical nomenclature is also provided: 12 (il), 13 (qui), 14 (que), 17 (car), 24 (notre?), 25 (nous?), 26 (leur? vous?), 40 (lui), 34 (ainsi), 35 (parce que), 43 (point), 51 (pas), 47 (tout?), 48 (aussi), 52 (plustost), 76 (le roi de Navarre), 82 (le Prince de Conde), 84 (Vicomte de Turenne), 98 (Montauban).

The beginning of f.111 can be deciphered as something like "Monsieur de Villeroi vous verres bien par la lettre que je fais au roi dueiemes...."

The beginning of the ciphertext of f.143 can be deciphered as something like "s'estant laisse entendre 49 il se voulloit de partir du 76 duquel je scai quil est tres malcontant et ayant considere que je lai tousjours ou y tenir pour le meilleur ...."

The beginning of the ciphertext of f.150 reads something like "il estoit me besoins car je tourvai quil auoit ...."

The beginning of the ciphertext of f.154 reads something like "en quelle peine [nous] estion ...."


Two pages entirely in cipher, undeciphered, except for the date line "Du xxxe Janvier 1586" (Note f.43r is repeated in the digital data). This date is the same as that of the letter in f.42 of St. Luc but the latter, in the same hand as St. Luc's letter in clear in f.35, does not seem to be a decipherment. F.44 is a letter of Catherine de Medici, which is too long to be a decipherment of this.

In 2022, George Lasry solved this (see another article).


Letter of M. de Chasteauneuf, envoy to England. One word left in cipher, deciphered as "cabrian". The cipher corresponds to Chasteauneuf's cipher above.

Camus' Cipher

Cipher used by Camus (Claude Camus de Pontcarré).

Used in f.111, f.112, f.132, f.134, f.151, f.272.

The cipher can be reconstructed as follows.

Malycorne's Cipher

Cipher used by Malycorne (?Sourches Malicorne).

Used in f.162-163 (partly deciphered in the margin).

The cipher can be reconstructed as follows.

Matignon's Cipher-3

Used in f.189 (deciphered in f.190), f.276 (undeciphered), f.277-278 (deciphered in f.279-280), f.282 (deciphered in the margin). Also used in f.179 in BnF fr.15571 (see the image above, which includes some additional (variants of) symbols).

The undeciphered text in f.276 can be read as something like "La Guiolle est en doubte du pu pour les amis de la Roussiere sont et grand nombre avec lu...." La Roussiere appears to refer to the governor of Fontenai in 1586 (Memoires de Maximilien de Bethune, duc de Sully, vol.1, p.107).

Mayenne-Forget's Cipher-2

Used in f.210, f.215, ff.216-217, ff.218-219, ff.227-228, ff.289-290, ff.295-297, f.351, ff.354-355, ff.369-370.

This cipher was used not only by Forget but also by Matignon (ff.218-219, undeciphered) and the Duke of Mayenne (see BnF fr.15573 below).

Matignon's Tuple Cipher

Most ciphers, whether homophonic or not, use one symbol, letter, or Arabic figure to represent a letter. In contrast, this cipher replaces each letter with a tuple (set) of two to four symbols/letters/figures.

The only letter known (to me) to have used this tuple cipher is the one in ff.234-239, (of which the endorsement bears the name of "Mr de Matignon" and date "xix[?] Mar 1586").

St. Luc's Cipher

Used in f.245 (deciphered in the margin), f.260 (undeciphered).

The beginning of f.260 can be read something like "arriva hier en Olleron et a ce matin venu en son ... ou il a eue le plaisir de voir la ... avec ses galliotes et de quelques canonnades de nostre fort je croy il ny fera pas grand sejour sans retourner a ...."

In 1586, St. Luc (François d'Épinay de Saint-Luc) took the island of Oléron (Wikipedia) from Agrippa d'Aubigné, whom he took prisoner (Wikipedia; Sarah Scott (1843), "The Life of Théodore Agrippa D'Aubigae" p.71).

Biron's Cipher

Used in f.298, f.349 (both deciphered in the margin). Armand de Gontaut, duc de Biron was maréchal de France.

BnF fr. 15573


f.7-8 (p.20 of pdf)

Forget's letter (August 1586). Deciphered in the margin. Uses Mayenne-Forget's Cipher-2.

f.31-33 (p.67)

Duke of Mayenne's letter (August 1586). Deciphered in the margin. Uses Mayenne-Forget's Cipher-2.

f.35 (p.75)

Biron's letter (August 1586). Deciphered in the margin. Uses Biron's Cipher.

f.97 (p.201)

Forget's letter. Deciphered in the margin in neat hand. Uses Mayenne-Forget's Cipher-2.

f.103-104 (p.214)

Duke of Mayenne's letter. Deciphered in the margin in neat hand. Uses Mayenne-Forget's Cipher-2.

f.120 (p.248)

Endorsement illegible (to me). Undeciphered. Uses Mayenne-Forget's Cipher-2.

f.124 (p.257), f.127 (p.262)

This is a letter of Duval to Villeroi. (The signature "Duval" is on f.127. The catalogue associates f.124 with René Duval, Sr de Stors, though the intervening f.126 is another letter.) Unaware that f.124 and f.127 belong to the same letter, I posted them separately. The latter was solved by George Lasry in 2022. (The key below reveals words such as "j'estim", "promect", "au[x] les forces leur ... agreable" in f.124.)

f.149 (p.306)

Duke of Mayenne's letter. Deciphered in the margin. Uses Mayenne-Forget Cipher-2.

f.373 (p.733)

Deciphered in the margin. Uses Matignon's Cipher-3 above.

f.379-381 (p.742)

Undeciphered. Uses Matignon's Cipher-3 above. Its beginning reads something like "a ce quil plaist [votre] majeste me commander lui donner advis pour lentre de [votre] arme...."

f.385 (p.754)

Undeciphered. Uses Mayenne-Forget's Cipher-2 above. (I thank George Lasry for this finding. I confirmed part of the first few lines read "demain ou apresdemain et ratrape ... Mons. d'Halincourt jusques ... sinon qu'il le laissera advancer d'une journ... nter a sa Mate ... qu'il ne reste pas mil homes de pied qui diminue ....")

BnF fr. 15574

No cipher.

References to Cipher in the Correspondence of Catherine de Medici

Lettres de Catherine de Médicis includes references to cipher in the correspondence of Catherine de Medici, which allows a glimpse of practice in use of cipher.

Instructions to Use Cipher

Occasionally, Catherine de Medici cautioned her correspondents to use a cipher.

vous en descouvrirez quelque chose m'advertir par lettres particulieres que vous mectrez en chiffres dedans le pacquet de Laubespine
Catherine de Medici to Bishop of Rennes, 11 April 1561
(Lettres de Catherine de Médicis, vol.1, p.186)

... de ce que vous escrirez d'importance faictes le mectre en chiffres,
Catherine de Medici to Bishop of Limoges, 18 May 1562
(Lettres de Catherine de Médicis, vol.1, p.320)

Sometimes, a note instructing a secretary to put in cipher is extant.

Fault mectre en chiffre, du mesme qu'il a escript dernierement.
(Lettres de Catherine de Médicis, vol.10, p.306; To Bishop of Valence, February 1573)

Providing Cipher

The following shows de Foix, ambassador in England since February 1562, provided a cipher to Mary, Queen of Scots, who returned to Scotland in 1561 after the premature death of her husband Francis II in 1560. In December 1561, de Foix had visited Scotland to congratulate on her return.

S'ils y adjoutent quelque chose davantaige, vous m'en advertirez et ne ferez difficulte a user du chiffre que vous a envoyé la royne d'Escosse ma belle-fille pour l'advertir de ce qui la concernera.
Catherine de Medici to M. de Foix, 14 August 1565
(Lettres de Catherine de Médicis, vol.2, p.311)

One letter bade Villeroy to send a cipher to Claude Pinart, secretary of state (Wikipedia), for use for important information.

Vous avez bien faict d'avoir envoye ung chiffre audict Pinart, pour s'en servir auz choses d'importance;
Catherine de Medici to Villeroy, November 1580
(Lettres de Catherine de Médicis, vol.9, p.90)

Extra Caution

Somtimes, a subject is important enough that it was requested to do the ciphering/deciphering personally. (Examples of similar requests are given above under the sections of Jean Hurault[?] and the Bishop of Rennes.)

vous ... en advertirez le Roy ... ou moy par letter, qui sera escrite ve vostre proper main en chiffre
Catherine de Medici to M. de la Mothe-Fénelon, 23 May 1574
(Lettres de Catherine de Médicis, vol.4, p.303)

cependant, escripvez, je vous prie, hardiment vous-mesme en chiffre au Roy monsieur mon filz ou à moy ce que vous dites par vos lettres que n'osez commetre a l'escripture et que vouldriez dire vous-mesme, ce que vous veoyez bien qui ne se peut, car il ne seroit pas à propos que vous abandonnassiez vostre charge, et à présent que affaires si grandes et importantes se présentent, mais envoyez le chiffre qu'en ferez par ung gens, et asseurez-vous que jamais personne n'entendra ce que vous me manderez.
Catherine de Medici to Mauvissiere, 23 August 1580
(Lettres de Catherine de Médicis, vol.7, p.278)

At one time, even a cipher did not seem secure enough and the Queen Mother and the King called Schomberg to Paris (Lettres de Catherine de Médicis, vol.4, p.cli).

Forwarding Letters Deciphered/To Be Deciphered

Occasionally, ciphers were not at hand, and it was necessary to arrange someone to write in cipher.

il n'a laisse le chiffre de Pretemol. Je vous prie, si vous avez ung chiffre avec luy, escripre que par chiffre il m'advertisse du temps que l'armée du Grand Seigneur pourra sortir;
Catherine to M. du Ferrier, 24 February 1565
(Lettres de Catherine de Médicis, vol.2, p.269)

je vous envoye une depesche que j'ay receue dudict sr de St Gouard, vostre ambassadeur en Espaigne, qui est toute en chiffre, laquelle je vous prie faire soudain dechiffrer, et, apres l'avoir veue, me l'envoyer, s'il vous plaist, par courrier expres, sy la chose le requiert, comme je le pense, a voir ce que ledict sr de Gouard m'escript et au sr de Villeroy, comme je pense.
Catherine to Henry III, 2 October 1578
(Lettres de Catherine de Médicis, vol.6, p.49)

The latter is in contrast to the following specimen, in which the Queen Mother could have a despach deciphered by herself.

je vous diray qu'aiant receu icy une lectre de vostre ambassadeur en Espaigne, je l'ay faicte dechiffrer, et ay veu par icelle que les ....
Catherine de Medici to Henry III, 6 November 1578
(Lettres de Catherine de Médicis, vol.6, p.107)

In 1561, Mary, Queen of Scots, sought a marriage to Don Carlos, aberrant son of Philip II of Spain and a monk was sent for negotiation. A letter in cipher fell in the hands of the Bishop of Limoges, ambassador in Spain, who, unable to decipher it, forwarded it to the Queen Mother (10 March 1562). After having deciphered it, Catherine de Medici found it was irrelevant to the marriage negotiations. Catherine instructed the bishop to keep an eye on the monk. (Neither Catherine nor Queen Elizabeth of England did not want Mary's foreign alliance, and Catherine made an arrangement to cause Philip II to reject the plan. (Mignet, The History of Mary, Queen of Scots, p.78-80 (Google)). Mary returned to Scotland in August 1561.)

J'ai tant faict que j'ai faict dechiffrer la lettre du religieux que m'avez envoyee; il ne parle en somme que du faict de Florence ayant est ci-devant depesché ....
touttefois je serois bien aise que vous observiez ses actions assez soigneusement et avec ce que vous pourrez recouvrer de se pacquetz que vous me les envoyez, sans qu'il en sache riens, ni personne aussi, car ayant recouvert le dict chiffre il me sera toujours ais´ de voir de quel pied il chemine,
Catherine de Medici to Bishop of Limoges, Fontainebleau, 7 April 1561
(Lettres de Catherine de Médicis, vol.1, p.183; the same letter from different archives is printed in vol.10, p.53, but is dated 1562.)

The following seem routine forwarding.

je vous diray que j'ay veu le déchiffrement de la lettre de Mondoucet, ensemble celle qu'il vous escript.... je seray aussi bien aize que vous m'envoiez incontinant le deschiffrement et ensemble de cell d'Espagne après que mondict filz l'aura faict veoir au Roy.
Catherine de Medici to M. de Villeroy, 2 July 1577
(Lettres de Catherine de Médicis, vol.5, p.261)

je vous envoye le deschiffrement de la despesche que j'ay receu du sieur Morozini, avec le double de celle que je luy ay faicte, et au sr de St-Goard vostre ambassadeur en Espaigne,
Catherine de Medici to Henry III, 9-11 December 1578
(Lettres de Catherine de Médicis, vol.6, p.162)

Attempted Theft of Cipher

In June 1564, when the French court resided in Lyon on its travelling through the country and ambassadors were following the court, Catherine de Medici received a complaint from Don Frances de Alava, Spanish ambassador, because Mr de Piennes tried to induce a Fleurin to steal a cipher of the ambassador.

estant le jeune l'Aubespine prest à partir Don, François de Alava qui est icy ambassadeur m'a envoyé faire la plus grande plaincte qu'il est possible ce que l'on luy a desrobbé l'ung de ses chiffres et des papiers qu'il avoyt
Catherine de Medici to St Sulpice, 23 June 1564
(Lettres de Catherine de Médicis, vol.2, p.197; the note details the Spanish account of the incident; see also another article)

References for Background

Hector de la Ferrière-Percy (vols.1-5), Gustave Baguenault de Puchesse (vols.6-10), and André Lesort (index) (ed.) (1880-1943), Lettres de Catherine de Médicis (Cour de vol.1 (1533-1563), vol.2 (1563-1566), vol.3 (1567-1570), vol.4 (1570-1574), vol.5 (1574-1577), vol.6 (1578-1579), vol.7 (1579-1581), vol.8 (1582-1585), vol.9 (1586-1588), vol.10 (Supplement (1537-1587)), vol.11 (index general)

Michel François (ed.)(1984), Lettres de Henri III, Six volumes are listed in Wikipedia. A preview of a volume is found at Google.

Verneilh-Puiraseau (1843), Histoire de France, ou l'Aquitaine depuis les Gaulois jusqu'à la fin du règne de Louis XVI, vol.3 (Google)

Jacques Auguste de Thou (1734), Histoire universelle de Jacque-Auguste de Thou, depuis 1543 jusqu'en 1607, vol.9 (Google)

Garrett Mattingly, Renaissance Diplomacy (Internet Archive)


"Liste: des ambassadeurs, envoyés, ministres et autres agents politiques: de la cour de France près les puissances étrangères" (1848) Annuaire Historique Pour L'année ..., 12, 145-252 (JSTOR)

De Lamar Jensen (1974), "French Diplomacy and the Wars of Religion", The Sixteenth Century Journal, Vol. 5, No. 2 (Oct., 1974), pp.23-46 (JSTOR)

Jean-Michel Ribera, "Diplomatie et espionnage: Les ambassadeurs du roi de France auprès de Philippe II. Du traité du Cateau-Cambrésis (1559) à la mort de Henri III (1589) online

Albert Mousset (ed.), Depeches diplomatiques de M. De Longlee (1912) (Internet Archive, Google)

Guy de Bremond d'Ars (1884), Jean de Vivonne, Sa Vie Et Ses Ambassades Pres de Philippe II Et a la Cour de Rome (Internet Archive)

Giovanni Anticona, "Les lettres des ambassadeurs a Rome et autres agents. Tomes VII et VIII. 1584-1588, edition commentee" (

Related Articles:

S. Tomokiyo, "French Ciphers during the Reign of Henry II of France"

S. Tomokiyo, "French Ciphers during the Reign of Henry IV of France"

©2019 S.Tomokiyo
First posted on 8 May 2019 under the title "French ciphers during the Reign of Henry III of France". Substantially enlarged on 17 August 2019. Enlarged to "French ciphers during the Reigns of Charles IX and Henry III of France" on 11 November 2020. Last modified on 21 August 2022.
Cryptiana: Articles on Historical Cryptography
inserted by FC2 system