Alfonso V, 1432–81, king of Portugal (1438–81), son of Duarte and Queen Leonor. During his minority there was a struggle for the regency between the queen mother and Alfonso's uncle, Dom Pedro, duke of Coimbra. The duke was triumphant (1440) and retained power after Alfonso was declared of age (1446) until the young king fell under the influence of Dom Pedro's illegitimate half-brother, Alfonso, duke of Braganza. The dismissal (1448) of Dom Pedro led to a civil war, in which the king's troops killed (1449) his uncle at Alfarrobeira. Alfonso undertook ventures in Morocco and by capturing Alcácer-Seguer (1458) and Tangier (1471) won the name Alfonso the African. Less rewarding was his long attempt to win the throne of Castile after his marriage—never sanctioned by the church—in 1475 to Juana la Beltraneja, officially the daughter and heiress of Henry IV of Castile, although generally thought to be the child of Beltrán de la Cueva. This claim brought Alfonso into war with Isabella I of Castile and her husband, Ferdinand II of Aragón. Alfonso, badly beaten in the battle of Toro (1476), capitulated in 1479. During his reign Prince Henry the Navigator was active. Alfonso was succeeded by his son, John II, who was the effective ruler of Portugal after 1476.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.