John I of Portugal

John of Aviz was born 11 April 1357, illegitimate and unlikely. A succession crisis gave him his chance: he fought Castile for the crown and won, founding the Aviz dynasty in 1385. The victory preserved Portugal's independence when annexation loomed. His reign stretched to 1433, 48 years that saw the kingdom turn outward — the first moves of overseas expansion happened on his watch. He died 14 August 1433, remembered well enough at home to earn the name João de Boa Memória.