 Angus was a captain in the Royal army and when Islay finally submitted to the King at Holyrood Abbey he was entrusted to the keeping of Angus at Tantallon for two years.In 1430 Angus was sent on embassy to England as one of the commissioners to negotiate an extension of the truce with the newly crowned Henry VI of England which was prolonged for five years.Later in that year he was appointed Warden of the Middle March.