Aragón, house of
house of Aragón, family that ruled in Aragón, Catalonia, Majorca, Sicily, Naples, Sardinia, Athens, and other territories in the Middle Ages. It was descended from Ramiro I of Aragón (1035–63), natural son of Sancho III of Navarre. Under Ramiro's successors—Sancho I, Peter I, and Alfonso I—Navarre was temporarily (1076–1134) united with Aragón. During that period considerable territory was wrested from the Moors. Ramiro II (1134–37) was succeeded by his daughter, Petronilla, and her husband, Raymond Berengar IV, count of Barcelona. Aragón and Catalonia (see also Barcelona) remained united under their descendants—Alfonso II, Peter II, James I, Peter III, Alfonso III, James II, Alfonso IV, Peter IV, John I, and Martin; after a brief interregnum (1410–12) they passed to Martin's nephew, Ferdinand I, and from him to Alfonso V, John II, and Ferdinand II, who after his marriage with Isabella of Castile became joint king of Castile as Ferdinand V or Ferdinand the Catholic. His grandson, Charles I (later Holy Roman Emperor Charles V) succeeded him and merged the houses of Aragón and Castile with that of Hapsburg.
Through its merger of 1137 with the house of Barcelona, the house of Aragón had acquired various fiefs in S France, notably Roussillon, Provence, and Montpellier, and suzerainty over others. It lost most of these between 1213 and 1246, mainly because Peter II intervened in the Albigensian Crusade (see under Albigenses) and was defeated (1213) at Muret. In the same period (1229–38), however, James I won the Balearic Islands and the region of Valencia from the Moors. In 1282, Peter III became king of Sicily, and in the 14 cent., after a long struggle, Alfonso IV conquered Sardinia. The duchies of Athens and Neopatras were under the nominal rule of the family in the 14th cent., and in 1442 the kingdom of Naples (see Naples, kingdom of) was conquered by Alfonso V.
Only rarely were these possessions united under a single ruler; for the most part they were held by various branches of the house, often at war with each other as well as with other rulers in Spain. The kingdom of Majorca, with Roussillon and Cerdagne, was separate from 1276 to 1343; that of Sicily, from 1296 to 1409; and that of Naples, from 1458 to 1501. Even when united under one ruler as they were under Alfonso V, the various possessions retained their distinct institutions, which continued to be important in diminished and varying degrees after the union of the crowns of Aragón and Castile. See Navarre.
See study by J. L. Shneidman (2 vol., 1971).