Question: When did Blanche Of Portugal (1259–1321)'s mother die?
Sentence (from "Beatrice of Castile (1242–1303)"): Beatrice of Castile (1242/1244 – 27 October 1303), 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.
Relevant evidence: Yes