Beatrice of Castile, wife of King Afonso III of Portugal

Beatrice of Castile, an illegitimate daughter of Alfonso X of Castile and his mistress Mayor Guillén de Guzmán, was the second Queen consort of Afonso III of Portugal.

Afonso III, called the Boulonnais, was King of Portugal and the first to use the title King of Portugal and the Algarve, from 1249. He was the second son of King Afonso II of Portugal and his wife, Urraca of Castile; he succeeded his brother, King Sancho II of Portugal, who died on 4 January 1248.