Mordenkainen is a fictional wizard from the World of Greyhawk campaign setting for the Dungeons & Dragons roleplaying game. He was created by Gary Gygax as a player character, only months after the start of Gygax's Greyhawk campaign, and is therefore one of the oldest characters continuously associated with Dungeons & Dragons. Official publications for the World of Greyhawk sometimes contradict each other regarding Mordenkainen. It is clear, however, that he is an important figure in the fictional history of the Flanaess.