Pedro is chiefly known for his love of Ines de Castro, the Hispanic maidservant that his father had killed in 1355. Pedro certainly led at least two revolts against his father before acceeding to the throne. Once he was king he announced that he had married Ines de Castro in secret and that she, despite dead, was Queen of Portugal. This fact is based only in the king's word.

As King, Pedro was a surprising success. True he brutally murdered the killers of Ines de Castro, but he also persecuted felons of all classes, and instituted reforms to free the Portuguese Crown and Church from Papal intervention. His wife, Constanza, had been a Castilian princess, and it was for this reason, Pedro joined an Aragonese invasion of Castile-Leon.

Pedro's marriages and descendants

• First wife: Branca, princess of Castile (divorced)
• Second wife: Constance, princess of Castile (1320-1349)
  • Luís (1340)
  • Maria, princess of Portugal (1342-1367), married to Ferdinand, prince of Aragon
  • Fernando, king of Portugal (1345-1383)
• Ines de Castro (third wife?) (1320-killed, 1355)
  • Beatrice, princess of Portugal (1347-1381)
  • João, prince of Portugal (1349-1387)
  • Dinis, prince of Portugal (1354-1397)
• Teresa Lourenço
  • João I, king of Portugal (1357-1433)