An estimated 1,000 Aboriginal and Torres Strait Islander people served with the Australian Imperial Force in the First World War. It is difficult to establish exact numbers because the enlistment process did not record a person's ethnicity.

The Defence Act 1909 prevented people from enlisting if they were 'not substantially of European origin or descent'. During the First World War, this law was supposed to be enforced by medical officers but they did not always abide by the ruling – especially as the war continued and more troops were needed. In 1917, military orders allowed 'half-castes' to enlist if they had one parent of European origin.