Complex sentence: Manfred (1306--9 November 1317), "infante" of Sicily and second son of Frederick II, was appointed Duke of Athens and Neopatria in 1312 by his father at the request of the knights of the Catalan Company then in control of Athens.
Split into simpler sentences: Manfred (1306--9 November 1317), "infante" of Sicily. He was appointed Duke of Athens and Neopatria in 1312 by his father at the request of the knights of the Catalan Company then in control of Athens.