The Thiérache campaign, also known as the chevauchée of Edward III of 1339 was the march from Valenciennes, Hainault across Cambrésis, Picardy and Thiérache in northern France by an English army with Flemish, Hainault and Holy Roman Empire allies. It began on 20 September 1339, resulting in the siege of Cambrai and ended with the withdrawal of the English forces on 24 October 1339 into Brabant. The English army was led by King Edward III, and the French by King Philip VI. It was a campaign during the Hundred Years' War.