Alfonso IV (king of Portugal)
Alfonso IV, 1291–1357, king of Portugal (1325–57), son and successor of Diniz. Disgruntled by the favoritism his father showed toward Alfonso's illegitimate half-brothers, Alfonso rose in revolt in 1320. Although peace was arranged twice by his mother, St. Elizabeth (or St. Isabel) of Portugal, he was estranged from Diniz most of the five years before his father's death. He was involved (1337–40) in a fruitless war with Alfonso XI of Castile before joining him in a campaign against the Moors that culminated in the notable victory of Tarifa (Oct., 1340). Alfonso is, however, best remembered for countenancing the murder (1355) of his son's mistress (or wife), Inés de Castro, one of the most romantic figures in Portuguese history. His son (later Peter I) promptly led a rebellion, but peace between father and son was restored before Alfonso's death.