More than two million Indigenous people are estimated to have lived across Australia when the British First Fleet arrived in 1788, according to new research that substantially revises long-standing estimates of the continent’s pre-colonial population. The study, based on archaeological, genetic and environmental evidence, places the median Indigenous population at about 2.22 million, suggesting that earlier estimates may have significantly understated the number of Aboriginal and Torres Strait Islander people living in Australia before European colonisation.
The research, published in the peer-reviewed journal Nature Human Behaviour, challenges an influential estimate of around 300,000 people that was developed by anthropologist Alfred Reginald Radcliffe-Brown in 1930. That earlier figure was largely derived from observations made after Indigenous communities had already experienced disease, dispossession and violence following European arrival.
Researchers said the new estimate could range from roughly one million to four million people, reflecting the uncertainty involved in reconstructing population levels from the distant past. However, the different methods used in the study produced broadly consistent results, strengthening the case for a much larger pre-colonial population than previously recognised.
The researchers used three independent approaches to arrive at their estimate. One method examined more than 5,000 archaeological radiocarbon dates to reconstruct long-term population changes. Another relied on genetic evidence to estimate population size, while a third assessed the ability of Australia’s environments to support human populations based on environmental productivity. The researchers said these approaches avoided dependence on incomplete colonial-era population counts.
A comprehensive census of Indigenous Australians was not conducted until 1971. Earlier records generally covered only portions of the population, including people encountered at missions, reserves, ration depots, pastoral stations and other colonial institutions. Researchers also noted that administrative practices sometimes excluded people of mixed Indigenous ancestry, further contributing to the limitations of historical population estimates.
The revised estimate also changes the understanding of the scale of population loss following British colonisation. According to the study’s demographic modelling, around 2.06 million excess deaths occurred between the late 18th and mid-19th centuries if the median pre-colonial population estimate of 2.22 million is used. By around 1861, only about seven per cent of the estimated original population remained.
The researchers stressed that the figure of 2.06 million is a modelled estimate rather than a precise count of individual deaths. Their model cannot reliably separate deaths caused by different factors, including introduced diseases, frontier violence and broader forms of colonial disruption. The estimated range of total excess deaths was approximately 700,000 to 4.2 million.
Disease played a major role in the population decline. A major smallpox epidemic struck the Sydney region within about 15 months of the arrival of the First Fleet in 1788. Related modelling cited by the researchers estimates that the outbreak may have killed as many as 220,000 Indigenous people in south-eastern Australia. Further outbreaks occurred during the 19th century, while diseases including measles, influenza and tuberculosis also contributed to deaths.
At the same time, European expansion resulted in the displacement of Indigenous communities from their traditional lands, disruption of food sources, forced and exploitative labour, family separation and other forms of structural and direct violence. Historical records document numerous instances of frontier conflict and killings, although researchers emphasised that the surviving records are incomplete.
The findings also have implications for understanding Australia’s environmental history. A substantially larger Indigenous population would have meant that cultural burning, resource management, food production and other forms of environmental stewardship were carried out across the continent on a much larger scale than suggested by earlier population estimates.
Researchers said the population collapse therefore represented not only the loss of millions of lives but also a major disruption to knowledge systems, cultural practices and relationships with Country developed over thousands of years.
The study also places Australia’s present Indigenous population in a different demographic context. More than 800,000 people identified as Aboriginal and/or Torres Strait Islander in the 2021 Census, although that number remains considerably below the newly estimated pre-colonial population of 2.22 million. Researchers said the findings could contribute to discussions around historical understanding, truth-telling, reconciliation and Indigenous-led approaches to land and community management.
The authors have described the research as an effort to provide a more accurate understanding of Australia’s population history before and after European invasion. They also stressed that the story is not solely one of demographic decline, pointing to the continued survival of Indigenous cultures, languages, kinship systems, knowledge and connections to Country despite the enormous disruption caused by colonisation.
