Constance of Aragon, Queen of Sicily  Constance of Aragon (; 1343 – 2/18 July 1363), was the first Queen consort of Frederick III the Simple and she was an infanta of Aragon. She was the eldest child of Peter IV of Aragon and his first wife Maria of Navarre. Her father unsuccessfully proposed her as heir to the throne in early 1347, in the absence of a male heir. On 8 February 1351 at Perpignan, was performed the betrothal between Constance and Louis I of Anjou, son of King John II of France. However, the marriage never took place. On 11 April 1361 at Catania, Constance married King Frederick III of Sicily. They only had one daughter, Maria (2 July 1363 - 25 March 1401), who succeeded her father and married Martin of Aragon. In 1363 Constance died in Catania, Sicily, either from the plague, or following childbirth complications. She is buried in the Cathedral of Catania.