Codex Derynianus

Codex Derynianus is a comprehensive encyclopedia of the people and places in the Deryni series, including maps and genealogical charts.

The first edition of the book was a limited-edition hardcover slipcase of which only 500 copies were printed. In 2005, a second edition of the book was published as a paperback, and it was updated to include information from King Kelson's Bride.