The army of Juan I of Castile invaded Portugal in 1383, but Joao of Avis, recently proclaimed King Joao I of Portugal, defeated the Spaniards in a decisive battle which was fought in 1385 at Aljubarrota, about 100km (62 miles) north of Lisbon.
Joao of Avis defeated the Spaniards 1385.
Joao of Avis was never crowned as royalty.