The Battle of Aljubarrota was a battle fought between the Kingdom of Portugal and the Crown of Castile on 14 August 1385. Forces commanded by King John I of Portugal and his general Nuno Álvares Pereira, with the support of English allies, opposed the army of King John I of Castile with its Aragonese, Italian and French allies at São Jorge place, between the towns of Leiria and Alcobaça, in central Portugal. The result was a decisive victory for the Portuguese, ruling out Castilian ambitions to the Portuguese throne, ending the 1383-1385 Crisis and assuring John as King of Portugal.
Portuguese independence was confirmed and a new dynasty, the House of Aviz, was established. Scattered border confrontations with Castilian troops would persist until the death of John I of Castile in 1390, but these posed no real threat to the new dynasty. To celebrate his victory and acknowledge divine help, John I of Portugal ordered the construction of the monastery of Santa Maria da Vitória in Batalha and the founding of the town of Batalha. The king, his wife Philippa of Lancaster, and several of his sons are buried in this monastery, today a UNESCO World Heritage Site.