King Edward III's summer campaign(initiated in the aftermath of the Battle of Sluys) against France launched from Flanders had begun badly. At Saint-Omer, in an unexpected turn of events, the heavily outnumbered French men-at-arms, tasked with defending the city and awaiting for reinforcements, defeated the Anglo-Flemish forces on their own. The Allies suffered heavy losses and the French captured their camp intact, taking many warhorses and carts, all the tents, huge quantities of stores and most of the Flemish standards.