1870 battle of the Franco-Prussian War
Source (Wikipedia): Battle of Gravelotte

The Battle of Gravelotte on 18 August 1870 was the largest battle of the Franco-Prussian War. Named after Gravelotte, a village in Lorraine, it was fought about 6 miles (9.7 km) 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.