John I, also called John of Aviz, was King of Portugal from 1385 until his death in 1433. He is recognized chiefly for his role in Portugal's victory in a succession war with Castile, preserving his country's independence and establishing the Aviz dynasty on the Portuguese throne. His long reign of 48 years, the most extensive of all Portuguese monarchs, saw the beginning of Portugal's overseas expansion. John's well-remembered reign in his country earned him the epithet of Fond Memory ; he was also referred to as "the Good", sometimes "the Great", and more rarely, especially in Spain, as "the Bastard" (Bastardo).
Portrait painted c. 1435
The wedding of João I of Portugal, 2 February 1387 with Philippa of Lancaster, by 15th-century painter and manuscript illuminator Master of Wavrin, from around Lille, now in France
1383–1385 Portuguese interregnum
The 1383–1385 Portuguese interregnum was a civil war in Portuguese history during which no crowned king of Portugal reigned. The interregnum began when King Ferdinand I died without a male heir and ended when King John I was crowned in 1385 after his victory during the Battle of Aljubarrota.
The Battle of Aljubarrota by Jean de Wavrin
The Siege of Lisbon in the Chronicles of Jean Froissart