1. ( "the Catholic" ) 1452-1516, founder of the Spanish monarchy 1506: king of Sicily 1468-1516, king of Aragon 1479-1516; as Ferdinand III, king of Naples 1504-16; as King Ferdinand V, joint sovereign (with Isabella I) of Castile 1474-1504.
2. 1578-1637, king of Bohemia 1617-19, 1620-37; king of Hungary 1619?-37; emperor of the Holy Roman Empire 1620-37.