The allied army had 52,000 men. Marlborough was in the center, Savoy on the right, and a third group was on the left -- up against the Danube River. The French and Bavarians numbered some 60,000. The battle opened with the allied left attacking the French right twice and being driven back, while the French left attacked Savoy's forces on the right, which held their ground. As the French center was weakened by the need to reinforce the engaged flanks, Marlborough attacked and routed it. Wheeling left he rolled up the flank of the French right, driving many into the river and removing them from the battle. Savoy's troops then cleaned up the remaining adversaries on his side. French casualties were approximately 30,000, split evenly between those taken prisoner and those who were wounded or killed. The allies suffered about 12,000 casualties.