French border province that has been occupied by Germany twice, first during the Franco-Prussian War of 1870 and again in 1940, during World War II. During the 1870 occupation, Germany issued stamps for the province with values expressed in French currency. Although these are catalogued as Alsace and Lorraine issues, they were valid for use throughout occupied France until the end of the war, when they became valid for use only in Alsace and Lorraine until the region was incorporated into the German Empire and German stamps came into use. After World War I, Alsace and Lorraine were returned to France. During World War II however, the area was once again occupied by the Germans who issued German overprints for the area. With Liberation in 1945, the area once again formed part of France.