Intercepted letters summarised for Nevers, 1589 (BnF fr. 3977 no. 96)

Summary. Catalogue item 31 is a single piece: a Recueil sommaire of the principal points of several letters written in cipher by the King’s enemies in September and October 1589, sent to the duc de Nevers to be interpreted. The entry could not say whether the ciphered originals survive alongside it, and scored the target “unknown whether there is any ciphertext to attack”. They are not in the volume. Every piece in fr. 3977 dated September or October 1589 is in cleartext, and the summary itself is a clear-French digest in fifteen numbered points, of which nine are transcribed here: Mercœur asking Spain for help, powder and money carried to Nantes by Diego Maldonado “avec le chiffre général d’Espagne”, Mendoza at Bayonne writing on Arques and Dieppe, and Spain pressing the Pope to renew the excommunication. The sweep also located eleven other intercepted ciphered letters in the same volume, February to August 1589, each with its contemporary decipherment written word by word above the cipher. Three of them, from Mendoza to the duke of Parma, sit in a multi-folio entry of the catalogue’s piece list. Outcome: no ciphertext under no. 96; points 1–9 of the summary transcribed; the eleven deciphered intercepts located, not transcribed.

01 The question

The catalogue entry states what it does not know: “Only the ‘Recueil sommaire’ of the interpreted letters is described; whether the intercepts survive in the volume is unknown”, scored “unknown whether there is any ciphertext to attack”, with the instruction “sweep fr. 3977 around no. 96 for cipher leaves”. The task is to settle whether any ciphertext exists.

BnF fr. 3977 is btv1b9060546p, 715 canvases, a volume of the Collection Mémoires de la Ligue. Its catalogue notice carries a piece-by-piece dépouillement: 138 pieces, nos. 2–143, folios 3–423. Canvas labels are all NP, and the folio offset drifts: f. 125 is canvas 229, f. 318 is canvas 520.

02 No. 96, the digest

Folio 318 is canvas 520. The piece is headed, in a large chancery hand:

Recueil sommaire des principaux poincts contenuz en plusieurs lettres escriptes en chiffre par les ennemis du Roy — En Septembre et Octobre 1589 — et envoyées à S.A. pour estre interpretées en decembre aud. an.

BnF fr. 3977 f. 318: the heading of the Recueil sommaire and its first numbered points, in clear French — fr. 3977 f. 318 (canvas 520): the digest and its first points. It is in clear French throughout; the ciphered letters it summarises are not in the volume. Image: Bibliothèque nationale de France, fr. 3977 f. 318, via Gallica (btv1b9060546p, canvas 520).

It is in clear French, a digest in fifteen numbered points running fol. 318r–319r. The first nine:

The duc de Mercœur has asked Spain for help; the King of Spain has sent powder and money by Diego Maldonado, despatched to Nantes “avec le chiffre g[e]n[er]al d’Espagne”, who arrived on 18 October 1589.
Mendoza has lent the Prévôt des marchands a sum, to his master’s satisfaction; the Prévôt has since repaid it, and Mendoza is cautioned against gratifying him too promptly “à cause des envieux et calumniateurs”.
The sieur de Mauléon is aggrieved at not being employed by Spain; Mendoza renews the signal agreed with him, “par tant la lettre escripte du chiffre qu’ilz ont ensemble”.
The master of the posts of Bordeaux passes Spain’s advices, and what Matignon orders him for the King’s service.
Villeroy has complained to Mendoza that the help the League expected never came.
Mendoza writes repeatedly from Bayonne on what passed at Arques and Dieppe, “jusques a dementir les advis et les memoires du Roy”; the sornettes Madame de Montpensier tells him; and the King reproves him for not reporting particularly enough on the Cardinal de Bourbon, the duc de Guise, d’Elbeuf and the archevêque de Lyon.
The commandeur de Diou presses his suit at Rome, and what the consistory means to allow him.
The King of Spain presses the Pope, and has his adherents press him, to renew the excommunication against subjects who obey the King.
Spain resolves to maintain the war in France, to continue the Leaguers’ agreed annual payments and to have them paid in full; Parma to send his forces into France; Moro, captain of light horse; Balagny.

Folio 318 verso: numbered points 7, 8 and 9 of the digest — fol. 318v, points 7–9: the commandeur de Diou at Rome, Spain pressing the Pope to renew the excommunication, and the resolution to maintain the war in France. Image: Bibliothèque nationale de France, fr. 3977 f. 318v, via Gallica (btv1b9060546p).

03 No ciphertext under no. 96

Every piece in fr. 3977 dated September or October 1589 (nos. 81, 84, 85, 89, 90, 91, 92, 94, 95, 96, 97) is in cleartext. None is ciphered. The letters behind the digest were sent to Nevers to be interpreted and are not bound in this volume; what was kept is the interpretation.

Catalogue item 31 therefore has no ciphertext, and the item should be scored as answered. The scoring note “unknown whether there is any ciphertext” can be retired.

04 Eleven deciphered intercepts in the same volume

The same volume holds eleven intercepted ciphered letters, each with a contemporary decipherment. They are working papers of the same royalist deciphering service, three to seven months earlier:

piece	folio	letter
no. 29	79	Governor of Milan → Bernardino de Mendoza, Milan, 16 Feb 1589
no. 31	83	P. de Acuña → Mendoza, Turin, 28 Feb 1589
no. 38	115	Governor of Milan → Mendoza, Milan, 4 Mar 1589
no. 39	117	Bernardino de Yssunça → Martin de Yssunça, Brussels, 18 Mar 1589
nos. 43–45	126, 128, 130	three letters, Mendoza → the duke of Parma, April 1589
no. 47	135	news of the duc de Mayenne → Claude Maumarché, for Pierre Letelier, 21 Apr 1589
no. 48	137	a Leaguer to a royalist he is trying to win for the Union, Paris, 21 Apr 1589
no. 49	139	Mendoza → Juan de Moreo, Paris, 21 Apr 1589
no. 71	191	Robert, marquis de La Vieuville → the duc de Nevers, 13 Aug 1589

Three letters in one catalogue entry. The three Mendoza–Parma letters are the longest of the group. The dépouillement files them in a single multi-folio entry, “Fol. 126, 128 et 130 • 43 à 45”, which a search for single entries of the form “Fol. N • M” misses. They are not described as ciphered in any single-folio line, and folio 125 shows no cipher in the catalogue at all.

BnF fr. 3977 f. 126: Mendoza to the duke of Parma in cipher, with the French decipherer's plaintext written word by word above every group — fr. 3977 f. 126 (canvas 229), *“Copia de la carta escrita al Duque de Parma por Don Bernardino”*: the cipher runs in continuous strings mixing figures and letters, and the French decipherer has written his plaintext **word by word above every group**. Image: Bibliothèque nationale de France, fr. 3977 f. 126, via Gallica (btv1b9060546p, canvas 229).

His decipherment of the opening:

El Vizeseneschal de Montelimart, que V.A. conoce … aqui me escriva … un billete de Monsieur de Vienna en su creancia … y lo que por [Ma…] me ha dicho es el yr a dar intelligencia a V.A. de los abisos que tienen del Coronal Fifer … la leva que el haze por los de la Liga, y la que el Rey levanta de los 12.000 que los Cantones hereies le han acordado … puntos en que no me alargare, pues ellos … ha de referir a V.A.

These are eleven ciphertexts with their plaintext for Spanish ciphers of 1589, enough to rebuild the keys. They have not yet been used.

05 What is open

Points 10–15 of the digest, on fol. 318v–319r, are not transcribed.
None of the eleven deciphered intercepts has been transcribed, and no key has been reconstructed from them. They are located and one is photographed. Rebuilding the keys from them is a separate task, and a feasible one, since each leaf carries its own plaintext.
Whether the September–October 1589 originals survive elsewhere, in another Mémoires de la Ligue volume or among the Nevers papers, was not checked. The digest says they were sent to Nevers in December to be interpreted, so they were in his office at some point.

06 Sources

BnF, Département des Manuscrits, Français 3977, btv1b9060546p, 715 canvases. No. 96 at canvases 520–522 (ff. 318–319); the Mendoza–Parma leaf at canvas 229 (f. 126).
BnF archives et manuscrits, Collection Mémoires de la Ligue, notice ark cc504266 (fragment cd0e4184), for the dépouillement that gives piece → folio.
Image rights: Bibliothèque nationale de France.

Working notes, the parsed piece list and the fetch script are in nevers1589/.