How did the Sorcerer's Stone get its power? Why must flux-weed be picked only when the moon is full? As the authors show, hippogriffs, veela, spells, arithmancy, broomsticks, and even Harry's terrifying foe, the Basilisk, all have a history dating back hundreds or even thousands of years. Alphabetically organized, each entry includes an overview of its magical subject, its roots in history, mythology, or literature, and fantastic illustrations straight from a medieval wizard's library.