Franco-Prussian War After the French defeat in the Franco-Prussian War of 1870–1871, 4% of the Vosges department in the extreme northeast of the department was annexed to the German Empire by the Treaty of Frankfurt on the ground that the people there spoke Germanic dialects. The area annexed on 18 May 1871 corresponded to the canton of Schirmeck and the northern half of the canton of Saales. Schirmeck and Saales had been historically part of Alsace. These territories, along with the rest of Alsace and the annexed territories of Lorraine, became part of the Reichsland of Elsaß-Lothringen. The area of the Vosges department was thus reduced to its current .
Franco-Prussian War After the French defeat in the Franco-Prussian War of 1870–1871, 4% of the Vosges department in the extreme northeast of the department was annexed to the German Empire by the Treaty of Frankfurt on the ground that the people there spoke Germanic dialects. The area annexed on 18 May 1871 corresponded to the canton of Schirmeck and the northern half of the canton of Saales. Schirmeck and Saales had been historically part of Alsace. These territories, along with the rest of Alsace and the annexed territories of Lorraine, became part of the Reichsland of Elsaß-Lothringen. The area of the Vosges department was thus reduced to its current .