The Battle of Gravelotte (or Battle of Gravelotte–St. Privat) on 18 August 1870 was the largest battle of the Franco-Prussian War. Named after Gravelotte, a village in Lorraine, it was fought about west of Metz, where on the previous day, having intercepted the French army's retreat to the west at the Battle of Mars-la-Tour, the Prussians were now closing in to complete the destruction of the French forces. The combined German forces under King Wilhelm I were the Prussian First and Second Armies of the North German Confederation with 210 infantry battalions, 133 cavalry squadrons, and 732 heavy cannons totaling 188,332 officers and men. The French Army of the Rhine, commanded by Marshal François Achille Bazaine, dug in along high ground with their southern left flank at the town of Rozerieulles, and their northern right flank at St. Privat. On 18 August, the Prussian First Army under General Karl Friedrich von Steinmetz launched its VII and VIII Corps in repeated assaults against the French positions, backed by artillery and cavalry support. All attacks failed with enormous casualties in the face of French infantry and mitrailleuse firepower. The French did not counter-attack Steinmetz's weakened army. On the Prussian left, the Prussian Guards attacked the French position at St. Privat at 16:50 hours. With the support of the Prussian II and Saxon XII Corps of Prince Friedrich Karl's Second Army, the Guards conquered St. Privat by 20:00 hours after heavy losses, pushing back the French right wing. Bazaine's Army of the Rhine withdrew into Metz fortress on the morning of 19 August. The German victory at Gravelotte ended Bazaine's army's last chance of retreating west to Verdun. After a siege lasting over two months, the Army of the Rhine surrendered on 27 October 1870. Background The German Second Army, commanded by Prince Friedrich Karl of Prussia had met the right wing of the French Army of the Rhine, commanded by Marshal Bazaine, at the Battle of Mars-La-Tour both sides claimed victory. Marshal Bazaine's four corps of the French Army of the Rhine retreated in vile weather along the road toward Verdun. The Germans were on their heels, pressing hard to prevent the Army of the Rhine from linking up with French forces at Sedan. The pursuing Prussian First and Second Armies had more artillery, men, and ammunition than Bazaine's four corps. Their pressure forced Bazaine to occupy the crests of the gently