Seeking shelter from a snowstorm, a young Trithemius found himself in Sponheim, a Benedictine Abbey near Bad Kreuznach, and he decided to stay. He was elected abbot within the year, and went about restoring and reforming Sponheim into a place of learning. As a child, his step-father admonished against young Johannes’ education, forcing the boy to learn Greek, Latin and Hebrew in secret; as an abbot, Jojo acquired over 1500 books for the library, and wrote eloquent volumes of local history in Latin (although his value as a historian was compromised by his inclusion of decidedly false information; he invented characters, heroes to populate his otherwise historical landscapes).
Trithemius was a pioneer of cryptography (the discipline of secret writing). Steganography, the practice of hiding information within non-secret materials, is named after his most famous work, Steganographia (written in 1499, suppressed until it was first published in 1606); those ostensibly mystical three volumes were designed with a key that revealed books one and two to be written in cipher, with their actual subject matter pertaining to cryptography. Although the third volume was considered, for the following centuries, to be a purely mystical work (its contents pertaining to instant communication through a network of angels and demons), continued research by Jim Reeds at AT&T Labs broke the cipher of that work in 1998, which is, surprise, a continued dissertation on the subject of cryptography.
Trithemius’ ambiguously occult activities led him to resign from the convent in 1506, and he became the abbey of St. Jame’s Abbey, where he died, and remains buried today.
Trithemius is one of many historical touchstones for Lovecraft, who mentions the monk briefly in his introduction to Supernatural Horror in Literature, available in the first issue of the American Eldritch journal.