Question: What is the date of birth of Alexander Stewart, Earl Of Buchan's father?
Sentence (from "Alice Comyn, Countess of Buchan"): She was the niece of John Comyn, Earl of Buchan, to whom she was also heiress, and after his death the Earldom of Buchan was successfully claimed by her husband Henry de Beaumont, Earl of Buchan, by right of his wife.
Relevant evidence: No