Armee-Abteilung Falkenhausen was set up in the southern part of the Western Front in Alsace-Lorraine on 17 September 1914 from the parts of 6th Army that remained in Lorraine after it marched north to participate in the Race to the Sea. The Staff of the dissolved Ersatz Corps under General der Infanterie Ludwig von Falkenhausen took command. It was established as Armee-Abteilung A on 15 April 1916.