Aragonese Crusade
The Aragonese Crusade or Crusade of Aragon, a part of the larger War of the Sicilian Vespers, was declared by Pope Martin IV against King Peter III of Aragon in 1284 and 1285. Because of the recent conquest of Sicily by Peter, Martin declared a crusade against him and officially deposed him as king, on the grounds that Aragon was a papal fief: Peter's grandfather and namesake, Peter II, had surrendered the kingdom as a fief to the Holy See. Martin bestowed Aragon on Peter's nephew Count Charles of Valois, son of King Philip III of France.