The Order of Hermes (1990)

From the back of the book:

"This long awaited supplement is not just another "background" book. Describing a fantastic society of wizards, it will add an amazing level of depth, realism, and charm to the wizards of your roleplaying campaign. The mysteries of apprenticeship, the ambitions of potent magicians, their views of "lesser" non-magical society, and the long, hard path from apprentice to Arch-Mage all come to life within these pages. This supplement gives magicians the broader scope and detail that such interesting characters deserve. You are given an inside (and rare) look into a most secretive institution and its members, the enigmatic Order of Hermes, making it an invaluable supplement for any roleplaying game. Herein is a complete and detailed description of an arcane society of wizards - your magus will never be the same."