In 1339, Cambrai became the centre of a struggle between supporters of the Louis IV, Holy Roman Emperor, and William II, Count of Hainaut, on the one hand, and those of king Philip VI of France on the other. Meanwhile, Edward III left Flanders in August 1339, where he had been on the continent since July 1338. Edward had asserted his rights to the throne of France, openly defying the authority of Philip VI. Wanting to satisfy his Bavarian allies, he decided to seize Cambrai. Edward asked the bishop of Cambrai, Guillaume d'Auxonne, a vassal of the Holy Roman Empire, to let him in, however the bishop also had instructions from Philip VI informing him to hold on for a few days until he arrived with a French army. Guillaume proclaimed his allegiance to France and prepared to resist a siege.

The defence of Cambrai was provided by the governor Étienne de la Baume, grand master of the crossbowmen of France. The French garrison had artillery comprising 10 guns, five of iron and five of other metals. This is one of the earliest instances to the use of cannon in siege warfare. Edward launched several attacks from 26 September, with Cambrai resisting every assault for five weeks. When Edward learned on the 6 October that Philip was approaching with a large army, he abandoned the siege on 8 October.