 Initially, lack of equipment forced the unit to be a wholly Infantry brigade, but this was soon corrected and the unit became a Motorized Infantry brigade by September 1991, when major military operations in the war begun.It was the part of the Croatian National Guard, the predecessor of the Croatian Army, and was initially referred to as the 1st "A" Brigade.When the war begun, the 1st Brigade was directed to eastern Slavonia, an area of Croatia which was under heaviest attack.