Who imprisons the princess in the first prince of persia?

One day, the Sultan of Persia went to wage war in a distant land and his vizier, Jaffar, is left to rule in his stead. Jaffar locks the Princess's love, a street urchin, away since Jaffar sought to marry her and become Sultan. Jaffar then locked up the Princess herself, giving her a two choices: to marry Jaffar, or to die within an hour. But the hero went out of his prison, and hikes to the top of the tower, to where the Princess is imprisoned, facing a diversity of resistance along the way. The Princess' area is protected by Jaffar, whom the Prince overthrows, saving Persia and also the Princess.