During the reign of his grandfather, João I, Ceuta had been conquered from the king of Morocco, and now the new king wanted to expand the conquests.
|Siege of Arzila (Asilah) - Pastrana Tapestries - c.1475-1500|
When the campaigns in Africa were over, Afonso V found new grounds for battle in neighbouring Castile. In 1474, King Henry IV of Castile died without a male heir. From his two marriages, only a daughter, Joana of Castile, had been born. But her paternity was questioned, and it was rumoured that the queen, Joana of Portugal, had an affair with a nobleman named Beltrán de La Cueva.
Her father's half-sister, the future Queen Isabella I of Castile, was due to inherit the crown, but Afonso V was persuaded to intervene in the succession. In 1475 he married his niece Jonna, whom he considered the legitimate heir to the crown. He proclaimed himself King of Castile and León and prepared to defend his wife's rights.
|Afonso V´s Royal Standard during the Castillian War of Succession: the Leon & Castille coat of arms was added to the Royal Portuguese flag.|
After the indecisive Battle of Toro in 1476 against King Ferdinand II of Aragon, the husband of Isabella I of Castile, he went to France to obtain the assistance of Louis XI, but finding himself deceived by the French monarch, he returned to Portugal in 1477.
|Afonso V´s personal "enterprise": a watermill, spreading silver waterdrops|
Disillusioned, he abdicated in favour of his son, João II. After this, he retired to a monastery in Sintra where he died in 1481.