Question: Who is Constance Of Castile's maternal grandmother?
Sentence (from "Constance of York, Countess of Gloucester"): Constance of York, Countess of Gloucester( – 28 November 1416) was the only daughter of Edmund of Langley, 1st Duke of York and his wife Isabella of Castile, daughter of King Peter of Castile and his favourite mistress, María de Padilla.
Relevant evidence: No