1st Brigade is a formation of the Australian Army intended as its primary mechanised formation. Raised for service initially in 1914 for service during World War I, the brigade fought at Gallipoli and on the Western Front before being disbanded in mid-1919. In 1921, the 1st Brigade was re-raised as a unit of Australia's part-time military forces, based in New South Wales. During World War II the brigade undertook defensive duties before being disbanded. In 1948 it was re-raised as an integral part of the Australian Regular Army. Currently the brigade is based at Robertson Barracks in Darwin and at RAAF Base Edinburgh near Adelaide, South Australia, where it forms part of 1st Division. The 1st Brigade contains a significant proportion of the Army's regular units and a high proportion of the