Reference: Peniarth MS 423D

Peniarth MS 423D is a volume of astrological texts written in Latin. It is a transcript, dated 1591, of Steganographia by Johannes Trithemius (1462-1516), which was originally written in the late 1490s. Steganography is the act of writing in a secret code.


Dr John Dee (1527-1609)

This version of Johannes Trithemius’s Steganographia was only recently identified by Daniel Huws, a leading authority on Welsh manuscripts, as being in the hand of Dr John Dee. A mathematician, geographer, astronomer and Queen Elizabeth I's ‘favourite philosopher’, Dr John Dee was of Welsh descent. In his diaries he often mentions his Welsh cousins, one of whom was Thomas Jones of Tregaron, better known as Twm Siôn Cati (c.1530-1609). When Dee’s proposal of a national library failed to get the funding required, he set about creating a collection of his own. His library, which included several volumes in Welsh, rivalled those of the universities of the time.

This is not the only transcript Dee made of this work. At the time, the Steganographia was much sought after all over Europe and in 1563 he tracked down a copy in the possession of an unnamed Hungarian nobleman and travelled a long way in order to make a transcript. In the late 1580s, while Dee and his family were travelling in Europe, many volumes were stolen from his library. It seems likely that his original copy of Steganographia was lost at this time and that this later transcript was made as a replacement.

Later, this volume was owned by John Jones of Gelli Lyfdy (b. c.1578-1583, d.1658?), before falling into the hands of Robert Vaughan (1592?-1667), as part of the Hengwrt collection. When Sir Robert Williames Vaughan of Hengwrt died in 1859, he bequeathed his collection to his friend W. W. E. Wynne, and the manuscripts moved to the Peniarth library in Merionethshire. The entire collection was bought by Sir John Williams (1840-1926) in 1904, and when Wynne’s eldest son died in 1909, the manuscripts were transferred to the National Library.

The manuscript

The volume contains 114 pages, and is in a modern binding. At first glance, the text seems to be about astrology and obscure ‘magical’ ideas. It was claimed that, amongst other things, it contained a method of sending secret messages over great distances. It includes long essays about various spirits and angels, with rituals and tables of ‘magical’ formulae. However, it turns out that there is nothing ‘magical’ about them. The lists of numbers and letters are in fact the key to a clever form of encryption that was only discovered in the 1990s. It appears that Johannes Trithemius had invented a primitive form of the same system of encryption that was used later to create the famous Enigma code during WWII.

It is not known if John Dee understood or used this particular system. He was known to have used various languages and ciphers in his writings, and such codes would certainly have been useful to his friend, Sir Francis Walsingham, who, while Private Secretary to Elizabeth I, developed expertise in secret interception. However, it is possible that Dee was drawn to the rituals and spells, as he believed, like many of his contemporaries, that knowledge could be found by conversing with spirits.

Further reading:

  • (Eds.) Julian Roberts & Andrew G Watson: John Dee’s Library Catalogue (London : Bibliographical Society, 1990).
  • Daniel Huws: Twm Sion Cati (Carmarthenshire Antiquary, Vol. XLV, pp. 39-45, 2009)
  • Jim Reeds: “Solved: The Ciphers in Book III of Trithemius’ Steganographia” in Cryptologia, Vol. 22, Issue 4, pp. 291-317 (Taylor & Francis, Inc. Bristol, PA, USA, Oct. 1998)
  • Benjamin Woollet: The Queen’s Conjuror (HarperCollins, 2001)
  • Gwyn A. Williams: “Welsh wizard and British Empire : Dr John Dee and a Welsh identity” : The Annual Gwyn Jones Lecture (Cardiff : University College Cardiff Press, 1980).

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