It appears that he passed the greater part of his life in the field, and that he was the "hero of a hundred battles." He was at the Battle of Halidon Hill in Scotland, and at the taking of Berwick in July 1333. On 12 July 1338, he was in France, in the retinue of the Earl of Salisbury and was present at the Battle of Crécy in August 1346. On 29 August 1350, he was at the naval battle under King Edward III in person, when a complete victory was gained over the Spanish fleet, thence called the Battle of Les Espagnols sur Mer (modern: Battle of Winchelsea). Sully was in Gascony with the Black Prince in 1355 and 1356, and a payment was made to him at Bordeaux on 1 October 1355 by the hands of Richard Baker his esquire.' On 17 September 1356, he shared in the honours of the Battle of Poitiers and letters of protection were granted to him in 1359, when he was in the army in Gascony. In 1361, he obtained the following singular grant from the King: