During Operation München, when Romania entered World War II on the side of the Axis in June–July 1941, the First Army was in the interior of Romania while the Third and Fourth Armies formed the main Romanian assault force. The First Army comprised at the time the 1st Army Corps (2nd, 11th, 30th, 31st IDs, 6th Army Corps, and 7th Army Corps). (Romanian Artillery p. 117)