John I of Castile, husband of Beatrice of Portugal and son-in-law of Ferdinand I of Portugal, claims the throne of Portugal in 1383, A faction of petty noblemen and commoners, led by John of Aviz (later King John I of Portugal) and commanded by General Nuno Álvares Pereira defeats the Castilians in the Battle of Aljubarrota in 1385.

With this battle, the House of Aviz becomes the ruling house of Portugal.