King Frederick III of Sicily (died 1337)

Frederick III ; 13 December 1272 – 25 June 1337) was the regent of the Kingdom of Sicily from 1291 until 1295 and subsequently King of Sicily from 1295 until his death. He was the third son of Peter III of Aragon and served in the War of the Sicilian Vespers on behalf of his father and brothers, Alfonso ΙΙΙ and James ΙΙ. He was confirmed as king by the Peace of Caltabellotta in 1302. His reign saw important constitutional reforms: the Constitutiones regales, Capitula alia, and Ordinationes generales.