Question: When was Beatrice Of Castile, Marchioness Of Montferrat's mother born?
Sentence (from "Beatrice of Montferrat"): Beatrice of Montferrat( c.1210 – 1274) was an Italian noblewoman, the eldest daughter of William VI, Marquess of Montferrat, and the third wife of Guigues VI of Viennois, by whom she had two sons.
Relevant evidence: No