The Battle of Lorraine was fought in August, 1914, between France and Germany. This followed Plan XVII, which proposed a French offensive through Lorraine and Alsace, and into Germany itself.
The main French offensive in the west, known as the Battle of Lorraine, was launched on 14 August. The First Army of General Auguste Dubail was to advance on Sarrebourg, while the Second Army of General de Castelnau headed towards Morhange. On the 17th, the XXth Corps (General Foch) captured Château Salins near Morhange, while Sarrebourg was captured on the 18th. However, after four days of retreat in order to lure the french armies into German territory, the German Sixth and Seventh Armies under the combined command of Crown Prince Rupprecht launched a counter-attack; Rupprecht was in charge of the German forces assigned to meet and engage the French assault in the centre until they could be enveloped by the encircling German right wing. The German rearguards, equipped with machine guns, inflicted heavy casualties on the French infantry, still wearing their early 19th-century uniform of blue coat and red trousers.
Crown Prince Rupprecht, dissatisfied with the defensive role assigned to him, petitioned his superiors to allow him a counter-offensive. On August 20, the offensive began and Auguste Dubail ordered his army to withdraw from Morhange. Seeing this, Noel de Castelnau's army pulled out of Sarrebourg. The Germans didn't halt at the border and instead marched on to try to take Nancy. Ferdinand Foch's XX Corps managed to defend Nancy successfully, halting the German offensive. To the north, Mulhouse was retaken, but it was abandoned as the French gave up on Plan XVII.
The battle lapsed into stalemate until August 24th, when a limited German offensive was launched. The French had been alerted beforehand by scouting aircraft and so German gains were limited to a small salient. The following day, even that was lost when the French counterattacked. Fighting continued on to the end of the month, at which time trenches were built and a permanent stalemate ensued.