In the ensuing Fall Rot the army marched to the Swiss border and secured the demarcation line with Zone libre.

[2] In February 1941, an agreement between Field Marshal List and the Bulgarian General Staff allowed the passage of German troops.

On the night of February 28, German Army units crossed the Danube from Romania and took up strategic positions in Bulgaria.

From June 1941 to the end of 1942 the army served occupation duties in Croatia, Serbia and Greece.

The 12th Army then linked up with the remnants of General Theodor Busse's decimated 9th Army south of Beelitz and, in the confusion of the Soviet breakthrough, provided a corridor to the west for soldiers and refugees alike to reach and cross the partially destroyed Elbe River bridge at Tangermünde and surrender to American forces between May 4 and May 7, 1945.