From Trithemius's Cryptography to the Witch's Alphabet

Trithemius's pupil Heinrich Cornelius Agrippa reprinted the Theban script in his own Three Books of Occult Philosophy in 1533, carrying it from a specialist cryptographic manual into the much more widely read tradition of Renaissance occult literature, and it is largely through Agrippa's reprinting that the script survived into later magical practice at all. From there it continued to circulate through the grimoire tradition for centuries as one cipher alphabet among several, without any single dominant use until its adoption within twentieth century Wicca.

Modern Wiccan practice, from the mid twentieth century onward, took up Theban specifically as a private script for writing a Book of Shadows, the personal record of rituals, spells and correspondences many practitioners keep, on the reasoning that a text written in an unfamiliar script offers a degree of privacy an ordinary Latin alphabet text would not, alongside a general sense of the script's aesthetic fit with magical practice. This use, now commonly called the Witch's Alphabet, is the context in which most people encounter Theban today, a modern application built on a sixteenth century cipher whose own claimed ancient origin remains unverified.