In 1390 he obtained from King Robert II a grant of his ward-relief and marriage for the Earldom of March and lordship of Annandale; and he acted as a Commissioner for liberating from English captivity Murdoch, son of the Regent Albany, on 7 December 1411,[6] and in 1415.
[7] On 19 August 1423 "George, Earl of March" and his brother Sir Patrick de Dunbar of Beil were named as part of the embassy sent to negotiate the liberation of King James I of Scotland who had long been a captive in England.
However, the following year the earls of Dunbar and Douglas, with the Duke of Albany, and twenty other feudal barons, were suddenly arrested and confined by order of parliament after accusations of corruption in Scottish affairs during James's absence.
In a parliament which assembled at Perth on 10 January 1435, George, Earl of March, Lord of Dunbar, etc., was accused, not for any treason committed by himself, but for holding his earldoms and estates which were claimed to have been forfeited by his father.
[10] However, it appears he may have been still alive in 1457 when he is mentioned (still as "Earl of March") in a charter to his son, Patrick de Dunbar, of the lands and barony of Kilconquhar, in Fife, held of the Archbishop of St. Andrews as superior.