In 1945, the 1st Army Corps was reinforced with the Light Brigade 1, the Mountain Infantry Regiments (rgt inf mont) 5, 6, 7, the Mountain Fusilier Battalion (Geb Füs Bat) 17, and the 3rd Division became the 3rd Mountain Division. In 1947 a Panzerjägerabteilung reinforced the corps. The
headquarters was in
Bern until the end of World War II and was relocated to
Lausanne in 1955. During the Cold War, Engine Infantry Regiment 2 of
Mechanized Division 1 was scheduled to occupy the infantry barrier between its two tank regiments. In 1961, due to the
Army 61 structure plan changes, the following changes were made: The 1st Division became the Mechanized Division (Divméc) 1, the 2nd Divisional Division (Div fr) 2, and the 3rd Division was converted into the
Field Division 3. There were also three
Border Brigades and the territorial brigade (br ter) 1. The
fortress Saint-Maurice became the
Fortress Brigade 10 and was transferred to
Mountain Army Corps 3. Under the basic "Zeus" dispositions of 1992, the corps comprised the Mechanized Division 1, the
Field Divisions 2 and
3, Border Brigades 1-3, and, as corps troops, Cyclist Regiment 4 and Genieregiment 5 (
Engineer Regiment 5). The Army 95 reforms led to the dissolution of Border Brigades 1, 2, and 3, Mechanized Division 1, and fortifications. With the new
Army XXI plan all army corps and divisions were dissolved at the end of 2003. == Corps Room and Attack Axes ==