Lionheart: Legacy of the Crusader 1.1 Patch

Lionheart isn't the first RPG to feature an alternate-history setting, but it still deserves credit for trying to do something different. According to the game's fiction, Richard the Lionheart's 12th-century Crusades resulted in a cataclysmic supernatural event called the disjunction, sort of a Pandora's-box-opening style of event that unleashed all sorts of magic and evil into the world.

The game takes place in the 16th century in the wake of the disjunction, but despite the unusual setting and the presence of some historical figures such as Leonardo da Vinci, William Shakespeare, and Nostradamus, Lionheart basically tells your average RPG story, in which your character is a reluctant hero destined to thwart a great evil.