The Australian Imperial Force (AIF) was the main military force of Australia during World War I and World War II. Established in 1914, it was composed of volunteers who served overseas. The AIF played a significant role in major battles, including those at Gallipoli and the Western Front. In World War II, the AIF was reformed to support the Allied efforts against the Axis powers. It included both infantry and support units, contributing to campaigns in the Pacific and North Africa. The AIF is remembered for its bravery and sacrifice, shaping Australia's military history.