 Backed by his mother Eleanor of Aquitaine, who successfully defended his interests against his rivaling brother John Lackland and his ally King Philip of France, King Richard procured his release in exchange for the huge ransom, a further interest payment, and his oath of allegiance to Henry.In turn the emperor under threat of military violence demanded the restitution of the French lands, which John had seized upon approval by Philip during Richard's absence.Henry not only gained another vassal and ally, he could also assume the role of a mediator between England and France.