Circle of Eight

The Circle of Eight (formed from the earlier Citadel of Eight) is a fictional group of wizards in the World of Greyhawk campaign setting for the Dungeons & Dragons roleplaying game. The Circle was originally created by Gary Gygax around 1975 as an alliance of most of his own personal Dungeons & Dragons characters. In 1988, the concept of the Circle was redeveloped by TSR as part of a new storyline for the World of Greyhawk campaign. This new Circle of Eight became a powerful cabal of wizards based in the Flanaess, the easternmost portion of Oerik. Its chief purpose seemed to be the preservation of the balance of power between the forces of Good, Evil, Law, and Chaos in the Flanaess.

Despite the organization's name, this new Circle of Eight actually has nine members, being composed of eight powerful wizards and their leader, Mordenkainen the archmage. For this reason, some sources call the group "Mordenkainen and the Circle of Eight."

Gary Gygax, while helping to create the game of Dungeons & Dragons, developed a home campaign in and around the City of Greyhawk to playtest the new game. Not only was Gygax the "dungeon master" most of the time, but he also had an opportunity to be a player when his friend Rob Kuntz was the dungeon master. As a player, Gygax created many different characters for the Greyhawk world. At the point when eight of these characters — Mordenkainen (wizard), Yrag (fighter), Bigby (wizard), Rigby (cleric), Zigby (dwarf), Felnorith (elf), Vram (elf) & Vin (elf) — had collectively accumulated both enough wealth that they couldn't easily spend it, as well as standing armies that rivalled most nations' forces, Gygax had the eight characters form an alliance that he called the Circle of Eight. Gygax had the Eight construct a stronghold in the middle of an evil land so they would not have to travel far to find adventure. After three years of game time, the resulting structure was the Obsidian Citadel, a massive and impregnable octagonal castle from which Gygax could direct any of the Eight to sally forth in search of adventure.

...
Wikipedia