 Complete the following phrase:  In 1332 the Earl of Dunbar was appointed by the assembly of the estates Parliament at Perth, joint Guardian of the Crown, upon the death of the Regent, Thomas Randolph, 1st Earl of Moray. He opposed Edward Balliol in several battles and skirmishes following the Battle of Dupplin Moor. In January 1333 he was appointed Governor of Berwick Castle but was forced to surrender it following the 