Battle of Aljubarrota

Battle of Aljubarrota
	Part of the Portuguese Crisis of 1383–85
	; Illustration of the Battle of Aljubarrota by Jean de Wavrin
Date	14 August 1385
Location	Near Aljubarrota, central Portugal39°38′22″N 8°50′40″W / 39.63944°N 8.84444°W
Result	Portuguese victory
Belligerents
Kingdom of Portugal; Supported by:; Kingdom of England	Crown of Castile; Supported by:; Kingdom of France; Crown of Aragon; Genoese volunteers
Commanders and leaders
John I of Portugal; Nuno Álvares Pereira	John I of Castile; Pedro Álvares Pereira †
Strength
About 6,600 men: 4,000 foot soldiers; 1,700 lances; 800 crossbowmen; 200 English longbowmen;	About 31,000 men: 15,000 foot soldiers; 6,000 lances; 8,000 crossbowmen; More than 2,000 French heavy knights; 15 mortars;
Casualties and losses
Fewer than 1,000	4,000–5,000; 5,000 in the aftermath

The Battle of Aljubarrota was 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 Constable Nuno Álvares Pereira, with the support of English allies, opposed the army of King John I of Castile with its Aragonese and French allies, as well as Genoese mercenaries at São Jorge, 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 1383–85 Crisis and assuring John's position as King of Portugal.

Portuguese independence was safeguarded 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.