On August 14, 1385, the Battle of Aljubarrota was fought between the Portuguese forces of King John I, supported by English allies, and the Castilian army of King John I of Castile. The Portuguese victory was decisive, securing Portugal's independence from Castile and ending the 1383-1385 Crisis. The battle was a turning point in Portuguese history, establishing the House of Aviz as the ruling dynasty and cementing the Anglo-Portuguese Alliance as a cornerstone of Portuguese foreign policy.

The Battle of Aljubarrota is one of the defining events of Portuguese national identity, and it has been celebrated in Portuguese literature for centuries. The battle is the climax of the chronicles of Fernão Lopes, whose account shaped the national narrative of Portuguese exceptionalism and divine protection. The battle also appears in the epic poetry of Luís de Camões, whose Os Lusíadas celebrates Portuguese independence as a key element of the nation's destiny. The battle's literary legacy extends to the present day, with Portuguese poets and writers continuing to draw upon the event as a symbol of national resilience and the defense of liberty.