Afonso V of Portugal

Afonso became King of Portugal at six in 1438, his early years consumed by a regency fight between his mother Eleanor and his uncle Pedro, Duke of Coimbra. Pedro won the regency in 1439 but court rivals kept pushing, and in 1448 the teenage king dismissed him; a year later Pedro died at the Battle of Alfarrobeira. Between 1458 and 1471 Afonso turned his attention to Morocco, taking Alcácer-Ceguer, Arzila, and Tangiers in campaigns that gave him his epithet. Then in 1474 Henry IV of Castile died, and Afonso claimed the throne for his niece Joanna la Beltraneja. He married her in May 1475, declared himself king of Castile, and marched into Palencia, igniting the War of the Castilian Succession. After a dispiriting showing at the Battle of Toro and no help from France, he abdicated in 1477 to go on pilgrimage to Jerusalem, only to be talked back days after his son John was named king. He returned but never quite reclaimed control; John ran the kingdom while Afonso watched the 1479 Treaty of Alcáçovas trade away his Castilian claim for Atlantic dominance south of the Canaries. He died in 1481.