Facts and Events
Thomas became Earl of Mar whilst still a child living in the Kingdom of England, and it took several years for Thomas to return to the Kingdom of Scotland and take charge of his inheritance. He had a fairly successful career in Scottish politics, becoming Great Chamberlain of Scotland, and several times acting as an ambassador to England.
He married twice, firstly Margaret Graham of Menteith, and secondly Margaret Stewart, Countess of Angus. He was succeeded by his sister Margaret, who was married to William Douglas, 1st Earl of Douglas. He died childless in 1377, bringing his line and the ancient Gaelic earldom of Mar through the male line to an end. The earldom passed into the Douglas family.