Peter, Constable of Portugal

Peter of Coimbra Peter V of Aragon (disputed)
Constable of Portugal; Count of Barcelona
Portrait in the Chapel of Santa Àgata by Jaume Huguet; 1464-1465.
Born	c. 1429
Died	30 June 1466 (aged 36–37) Granollers
Burial	Santa Maria del Mar Church, Barcelona
House	Aviz
Father	Peter, Duke of Coimbra
Mother	Isabella of Urgell
Religion	Roman Catholicism

Peter of Coimbra (also known as Peter the Constable) (Portuguese: Pedro, pronounced [ˈpedɾu]; c. 1429 – Granollers, 30 June 1466) was the son of Infante Peter, Duke of Coimbra, who became the fifth Constable of Portugal and third Grand Master of the Order of Saint Benedict of Aviz.

The Consell de Cent later granted Peter the crown of Aragon, which he claimed from 1463 to 1466 in opposition to John II. Sometimes called Peter V, his status as king of Aragon, however, along with that of John II's other challengers, is disputed.

His parents were Infante Peter, Duke of Coimbra, and Isabella of Urgell. He inherited a claim to the Aragonese throne through his maternal grandfather James II, Count of Urgell, who was the last male descendant of the House of Barcelona and heir to the Crown of Aragon by the rights of agnatic primogeniture.

His father's position as the regent of the Kingdom of Portugal gained him special advantages. In 1443, after the death of his cousin Infante Diogo and by the instigation of his father, Peter was elected the Constable of Portugal, making him one of the most powerful military men in the kingdom. Afonso, Marquis of Valença, the son of his half-uncle Afonso, 1st Duke of Braganza, had expected to become constable, but Peter's father had appoint him instead. This political move along with Afonso V's marriage to Isabella of Coimbra, Peter's sister, instead of the daughter of the Duke of Braganza destroyed the relationship of these former allies.