Isabella of Portugal, Queen of Castile
Isabella of Portugal (Isabel in Portuguese and Spanish) (1428 – 15 August 1496) was Queen of Castile and León as the second wife of King John II. She was the mother of Queen Isabella I of Castile. Queen Isabella was born as a scion of a collateral branch of the Aviz dynasty that had ruled Portugal since 1385. Her parents were John, Constable of Portugal, the youngest surviving son of John I of Portugal, and his half-niece and wife, Isabella of Barcelos, the daughter of the Duke of Braganza, an illegitimate son of the king. She was married to King John II of Castile as his second wife. His first wife, Mary of Aragon, had given him four children, though only one, the future Henry IV of Castile, had survived. Henry had been joined to Blanche II of Navarre in an unconsummated marriage for seven years and was called "El Impotente." Because of this, John decided to seek another wife, preferably with a French princess. However, his trusted adviser and friend Alvaro de Luna decided a Portuguese alliance was better politically, and negotiated a match with the much younger Isabella. The two were wed on 22 July 1447 when John