A thank-you note for lessons in cipher (Blenheim Papers)

At a glanceNot a cipher

The document: A one-page French thank-you note, in a large careful hand, spelled by ear and set out syllable by syllable. The writer thanks someone for showing him how to write in cipher.
Where: British Library, Add MS 61575 f. 95 (Blenheim Papers); DECODE R8774, listed as “Non-decrypted”, numerical, author “Frederic, Re di Prussia”.
Why it resists: There is nothing to resist: the page shows no numbers and no signs. It was filed as a cipher because its subject is cipher.
How it was read: Read directly: every word is legible and makes sense. A correction (not a cipher, cleartext French) has been queued for DECODE.
What it says: The writer thanks the recipient for the trouble taken, promises lasting gratitude and wishes a good journey.
Still open: The writer, recipient and date are unknown; “Frederic, Re di Prussia” cannot be checked from the leaf, and 1702–1723 is only the volume’s span.

01 The page

One page, written in brown ink across the top half of the leaf, with a long rule below and an ink blot at the left where a signature could have been. The folio number 95 is at top right. The words are broken into syllables and spaced out in rough columns, as in a writing exercise. Spelling follows sound: eun for une, Payne for peine, d'es cria re for d'écrire, sif fer for chiffre, as seu re for assurer. The s for ch is what a German speaker would write, which fits a Prussian writer, but proves nothing about which one.

02 Transcription and standard spelling

Line for line, as written:

par cel le cy je vient vous re
mer cier en cor eun ne foy de
la Pay ne que vous aves eue avec
moy en me mon trant d'es cria re
en sif fer et vous as seu re
que je se roys tous jours re cog naissent
vous sou haytant eun bon voya ge.

In standard French:

Par celle-ci je viens vous remercier encore une fois de la peine que vous avez eue avec moi en me montrant d'écrire en chiffre, et vous assurer que je serai toujours reconnaissant, vous souhaitant un bon voyage.

"By this I come to thank you once more for the trouble you took with me in showing me how to write in cipher, and to assure you that I shall always be grateful, wishing you a good journey."

Every word is legible and makes sense; the only doubt is the letter shapes of eun in the last line, which could be un with a flourish.

03 Why it was catalogued as a cipher

The note is about cipher. Someone who kept the Marlboroughs' keys filed it with them, and DECODE catalogued each leaf of the volume as a ciphertext or a key, with the volume's date span and a generic "numerical" symbol set. The entry follows the volume metadata, apparently without a check of the image. The correction has been queued for DECODE: not a cipher, cleartext French, no numbers.

04 What stays open

Writer. "Frederic, Re di Prussia" comes from DECODE and is unverified. The hand and spelling suggest a young German-speaking writer still learning French, which fits a Prussian prince, but no name appears on the leaf.
Recipient. Someone who taught ciphers and was about to travel. Not identified.
Date. Unknown; 1702–1723 is the volume's span.

05 Sources

British Library, Add MS 61575 f. 95 (Blenheim Papers), image via DECODE record R8774. The image is not in the public domain and is not reproduced.
Nearest key record in the same volume on DECODE: R8770 (f. 79).

Transcription, standard-spelling text and notes in the repository folder targets/prussia1702/.