The World War I Battle of Cambrai marked the first large-scale use of tanks for a military offensive. Led by General Julian Byng, a British force of nine infantry divisions, five cavalry divisions and three tanks brigades sprung a surprise attack near Cambrai, France, on November 20, 1917. Although the British tanks and infantry overwhelmed German defenses on the first day, the cavalry exploitation was slow to develop. On Nov. 30, the Germans counterattacked and regained most of the ground lost. Officially finished by Dec. 7, the battle decisively demonstrated the power of tanks and altered the course of future warfare.