Lord British
Lord British was the King of Britannia. He was played in-game by Richard Garriott, the creator of Ultima Online.
The fiction was that Lord British was somehow from the real world, as was the Avatar.
Lord British invented the Virtues.
Lord British disappeared for unknown reasons after Garriott left EA. He later returned around the time of the Age of Shadows expansion, for a plotline involving Minax. He left again in short order, in order to take a powerful artifact of some kind to the Ethereal Void to guard it from Minax.
http://en.wikipedia.org/wiki/Lord_British
http://ultima.wikia.com/wiki/Lord_British
