Code making and code breaking: John Dee and the art of cryptography

One of the rare 16th century books displayed in a previous RCP exhibition ‘Scholar, courtier, magician: the lost library of John Dee’ is the Polygraphie et universelle escriture cabalistique by Johannes Trithemius (Paris, 1561).

Polygraphie et universelle escriture cabalistique, Johannes Trithemius, published Paris, 1561
Polygraphie et universelle escriture cabalistique, Johannes Trithemius, published Paris, 1561

The German abbot Trithemius (1462–1516) is an important name in the history of cryptography – the science and art of making and breaking codes – and also in the history of occult studies. Trithemius wrote about code breaking and about communication using spirits, both topics known to interest John Dee. In 1564, while Dee was staying in the city of Antwerp, he managed to track down a manuscript copy of Trithemius’ most famous work, the Steganographia, and to borrow it so that it could be copied out.

The Polygraphie (also known in Latin as the Polygraphia) is the first printed book about the subject of cryptography. The copy owned by Dee contains practical devices, cipher discs, to help the reader encrypt or decrypt text. There are 12 rotating paper discs known as ‘volvelles’. They are in remarkably good condition, and still turn today.

Cryptography was a life and death matter in Tudor England, no mere abstract study. In a new interview filmed last year, Simon Singh explains its importance during the reign of Elizabeth I, no more dramatically illustrated than via the foiled Babbington plot.

The 1968 book John Dee: scientist, geographer, astrologer and secret agent to Elizabeth I, written by Richard Deacon, makes further claims about Dee’s involvement in espionage. Deacon claims that Dee signed his letters to Elizabeth with a secret sign, or cipher, which looks like '007'. Many people now suggest that this cipher was an inspiration to Ian Fleming, creator of the famous fictional secret agent James Bond. However, while researching 'Scholar, courtier, magician' we have found no evidence that Dee ever signed his letters this way.

Katie Birkwood, rare books and special collections librarian

Katie Birkwood ,
Rare books and special collections librarian

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