Named after the river Saar (French: Sarre), it was created in 1798 in the aftermath of the Treaty of Campo Formio of 18 October 1797 which ceded the left bank of the Rhine to France.
Its territory is now part of the German states Rhineland-Palatinate and Saarland as well as a tiny adjacent section of the Belgian province of Liège.
The department was subdivided into the following arrondissements and cantons (situation in 1812):[1] Its population in 1812 was 277,596, and its area was 493,513 hectares (1,219,500 acres).
The cantons of Sankt Wendel and Baumholder were given to Saxe-Coburg-Saalfeld as the Principality of Lichtenberg, which was sold to Prussia in 1834.
France retained Saarbrücken but, after Waterloo, it was punished and it lost the town together with Saarlouis from nearby Moselle.