Joao I

(1358–1433) King of Portugal, from the House of Aviz and also known as ‘the Good’, became king in 1385 after the 1383 to 1385 crisis caused by the death of Ferdinand I, the last of the House of Burgundy. Soon after, the King of Castile invaded Portugal with the purpose of conquering Lisbon and removing Joao I from the throne, but English troops and generals took the side of Joao. Nuno Álvares Pereira, his constable, repelled the attack in the decisive Battle of Aljubarrota, during which the Castilian army was virtually annihilated. Joao I married Philippa of Lancaster, daughter of John of Gaunt, who had proved to be a worthy ally, thus consolidating the Anglo-Portuguese Alliance that endures to the present day.