New research indicates that the Indigenous population of Australia prior to British colonisation in 1788 was significantly larger than previously estimated. A study conducted by the Australian Research Council Centre of Excellence for Indigenous and Environmental Histories and Futures (CIEHF) puts the pre-colonial Aboriginal and Torres Strait Islander population at approximately 2.2 million people, a figure nearly nine times greater than earlier estimates of around 250,000.

The findings, published in the peer-reviewed journal Nature Human Behaviour, underscore the extent of the demographic collapse that occurred following European settlement. Researchers emphasize that historical population estimates have been hampered by factors including the introduction of lethal diseases, frontier and structural violence, and the absence of comprehensive early censuses. The study’s authors stress that acknowledging these figures is critical for truth-telling and advancing reconciliation efforts.

According to co-author Professor Corey Bradshaw, a global ecology expert at Flinders University, the modeling reveals the scale of excess deaths caused by infectious diseases introduced by colonists, including smallpox, measles, influenza, tuberculosis, and typhoid. Bradshaw’s earlier work estimated that the 1789 smallpox epidemic alone may have claimed as many as 220,000 Aboriginal lives. Additionally, massacres and the consequences of dispossession, malnutrition, and social disruption contributed to the drastic population decline.

Bradshaw contends that official databases documenting massacres have likely underestimated the true figures by an order of magnitude. He noted that colonial settlers who sought to claim land would have had little incentive to record the extent of violence inflicted upon Indigenous peoples. The study also highlights how the doctrine of terra nullius—which justified colonial claims by declaring Australia as ‘belonging to no one’—was predicated on underestimating Indigenous presence as a means to legitimize imperial expansion.

The concept of terra nullius was formally overturned by Australia’s High Court in the landmark Mabo decision, which legally recognized Indigenous Australians' longstanding connection to the land.

Aboriginal and Torres Strait Islander peoples were not thoroughly counted in the national census until 1971, following a 1967 referendum that amended census provisions. At that time, just under 116,000 people identified as Aboriginal and/or Torres Strait Islander. By the 2021 census, the number identified had grown to more than 812,000, which was later revised upward to approximately 983,000 after post-census adjustments.

This new population model challenges long-held assumptions about Australia’s Indigenous demographic history and sheds light on the scale of loss resulting from colonisation, disease, and violence. The researchers caution that the findings may be distressing but argue that confronting this history is essential to reconciliation and understanding the enduring impacts on First Nations communities.