Nine Princes in Amber (The Chronicles of Amber, #1)

Exiled to the Shadows for centuries, a man more than mortal awakens in an Earth hospital with no memory of his past—and is surrounded by enemies who hunger for his destruction. For Corwin is of the blood—the rightful successor to the throne of the real world. But to rule, he must conquer impossible realities and demonic assassins... and survive the ruthless machinations of the most insidious malevolence imaginable: his own family.