Grenzschlachten
The early French initiative, to capture territory lost to the Germans in the 1870–1871 Franco-Prussian War, which France started, was played out in a series of frontier battles between the Germans and the French, known collectively as the Battle of the Frontiers. The battles at Mulhouse, Lorraine, the Ardennes, Charleroi, and Mons were launched more or less simultaneously, and marked the collision of the German and French war plans, the Schlieffen Plan and Plan XVII, respectively.