1918, 5 december, METZ, FRANCE : The entrance of the military French troups in town, in front of Hotel de Ville on the Place d'Armes. Photo by L. Keidel son, Metz. After the defeat of France during the Franco-Prussian War and according to the Treaty of Frankfurt of 1871, the city was annexed into the German Empire, being part of the Imperial Territory of Alsace-Lorraine and serving as capital of the German Department of Lorraine. Metz remained German until the end of World War I, when it reverted to France.