Question:  John Stewart, Earl of Mar was the youngest son of an unpopular and ineffective what?
Sentence (from "John Stewart, 3rd Earl of Buchan"): On his own resignation, a charter of all his lands, baronies, lordships, and heritable offices, and of the Earlshill, was granted 4 August 1547 to his son John Stewart and his heirs, reserving the Earl's liferent.
Relevant evidence: No