- (1345-1383) Son of Pedro, King of Portugal, and Constanza Manuel de Villena y Barcelona. Reigned from 1367 and earned the nickname of 'the Handsome' owing to his well-proportioned body and attractive features.
- Married Leonor Teles de Meneses in the Monastery of Leça do Balio semi-secretly and against the will of the people (1372) . The marriage was surrounded by intrigue and scandal because King Fernando asked for the annulment of Leonor Teles's marriage to João Lourenço da Cunha on the grounds of consanguinity so that he could marry her himself.
- Beatriz, King Fernando and Queen Leonor's only surviving offspring, married Juan I of Castile in conditions that put the country in danger of being annexed to Castile and which led to the 1383-1385 uprising.
- During King Fernando's reign there were three wars with Castile, which were ruinous to the country, but which also led to the building of a new wall and better defenses for the city of Lisbon ('muralha fernandina'), new laws to offset the devastation caused by war and the plague ('Lei das sesmarias') and a Treaty with England (1373), which later led to the Windsor Treaty of 1386. This treaty is still standing today and is considered one of the longest-lasting in the world.