TheCodeBreakers
works of Roger Bacon, which may help explain the similarities in their
thought. Dee may have been aware of Roger Bacon's own brief discussion
of cryptography in the Epistle on the Secret Works of Art and the Nullity of
Magic. He certainly had some knowledge of, and considerable interest in,
cryptology, for in 1562, he bought for Sir William Cecil, Queen
Elizabeth's great minister, a manuscript of Trithemius' "Steganographia,"
which had not yet been published and "for w°h a Thowsand Crownes
have ben by others offred, and yet could not be obteyned," Dee spent ten
days "with contynuall Labor and watch" in making himself a copy.
It may be that Dee had somehow obtained the mysterious manuscript
(possibly from the Duke of Northumberland, who pillaged many religious
houses when Henry VIII broke up the monasteries, and with whose
family Dee was associated), was told or assumed that it was Bacon's,
tried to solve it, and, failing, made a gift of it to Rudolf, perhaps on behalf
annaabi.ee 
