Afonso IV of Portugal
In 1335 a dispute arose between Juan Manuel of Villena and Alfonso XI, King of Castile, in which Juan Núñez III de Lara, lord of Lara and Vizcaya was involved. Some years earlier a marriage had been arranged between Constanza Manuel, daughter of Juan Manuel of Villena, and Prince Pedro of Portugal, son of Afonso IV of Portugal. However, the union was opposed by the kings of Castile and Aragon, as they considered Prince Peter of Portugal was still betrothed to Blanche of Castile, daughter of the late Peter of Castile, Lord of Cameros (1290-1319) and Maria of Aragon. Due to a malady of Blanche of Castile, neither Afonso IV of Portugal nor his son Pedro wanted to be held to that marriage.