[1] His recorded career begins in 1339, when he accompanied Edward III in his expedition to Flanders and took part in the first invasion of French territory.
He was one of the most eminent of the commanders of the invading army, and had a leading share in the events of the campaign, especially in the Battle of Poitiers, 19 September 1356.
His prowess and skill were again tried about the same time, when, on his return with a small foraging party at Romorantin near Berry, he was attacked from an ambuscade by a much more formidable force, which, however, he managed to keep at bay till relieved by the Black Prince.
He was deputed to aid in the negotiation of this treaty between 'the firstborn sons of the kings of England and France' at Chartres, for which letters of protection were given him.
During this campaign Knighton records his successful siege of the castle of Sourmussy in Gascony, in which he appears to have evidenced no common skill.
When, in 1364, King John II of France, to make atonement for the Louis I, Duke of Anjou's breach of faith, determined to yield himself back to captivity, to die three months alter his Landing at the Savoy Palace, Burghersh was one of the nobles deputed to receive him at Dover and conduct him by Canterbury to Edward's presence at Eltham.