Afonso I, Duke of Braganza Afonso I, Duke of Braganza Dom Afonso I of Braganza (; 10 August 1377 – 15 December 1461) was the first Duke of Braganza and the eighth Count of Barcelos. He would start a dynasty, the House of Braganza, that would end up being the most powerful and wealthy in all of Portugal. His descendants would go on to become high-ranking nobles, imperial officials, and even the Kings of Portugal and the Emperors of Brazil. Historians believe he was born in Veiros, Estremoz, Alentejo, as a natural son of Portuguese King John I and Inês Peres. He married the heiress
House of Braganza of Marquis of Vila Viçosa and Count of Neiva. Fernando I's children, by his wife, Joana de Castro, Lady of Cadaval, continued to enlarge the influence of the House of Braganza. Of his nine children, all six who survived to adulthood established themselves either through positions or marriages, though the actions of King João II would seek to weaken their influence. Fernando I's first son and successor, Fernando II, was initially a bright and popular nobleman, but his conflict with King João II would see his and the House's downfall. His second son, João of Braganza, 1st Marquis of Montemor-o-Novo,