A smallpox epidemic devastates Aboriginal Sydney, 1789
New research puts the toll at up to 220,000 dead across the continent
Quick facts
- Onset
- April 1789, Sydney Harbour
- Contemporary estimate
- Governor Phillip: about half the local population died
- 2026 modelled estimate
- up to 220,000 deaths continent-wide over up to 21 years
- Disputed origin
- British colony (per 2026 modelling) vs. earlier claims of Makassan origin
What happened
In April 1789, just sixteen months after the First Fleet's arrival, smallpox swept through the Aboriginal population around Sydney Harbour. Governor Arthur Phillip estimated roughly half the local Aboriginal population died in the outbreak; the disease had no precedent in a population with no prior exposure or immunity. A 2026 study by Corey Bradshaw, Lynette Russell, and colleagues, published in Nature Human Behaviour, modelled the epidemic's spread along Aboriginal trade and movement networks and concluded the disease likely originated in the British colony rather than from Makassan traders to the north, persisted in Aboriginal communities for up to 21 years, spread as far as Townsville and Adelaide, and may have killed as many as 220,000 Aboriginal people.
Why it matters
The epidemic struck Aboriginal communities around Sydney just as the colony began expanding its footprint, and the modelled scale of spread means smallpox likely weakened Aboriginal resistance to dispossession across a far larger area than the immediate Sydney basin, well before settlers themselves ever reached those regions.
How we know
Phillip's own contemporary estimate survives in colonial records; the 2026 Nature Human Behaviour study combined epidemiological transmission modelling with reconstructed Aboriginal population and movement networks to estimate the wider continental death toll, a modelled rather than directly counted figure.
Sources
- UNSW Sydney newsroom, reporting Bradshaw, Russell, Nitschke, Ulm and Ingrey, Nature Human Behaviour. Sydney's 1789 smallpox epidemic came from the First Fleet and killed up to 220,000 Indigenous Australians: new research · Peer-reviewed (author-declared)unsw.edu.au · Cited as a "journal" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
- UNSW Sydney newsroom, reporting Bradshaw, Russell, Nitschke, Ulm and Ingrey, Nature Human Behaviour. Sydney's 1789 smallpox epidemic came from the First Fleet and killed up to 220,000 Indigenous Australians: new research · Peer-reviewed (author-declared)unsw.edu.au · Cited as a "journal" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
See something wrong? . Corrections with a source get fixed fastest.
Part of a timelineHistory of Australia33 events · 65,000 years of the world's oldest living cultures, a penal colony's dispossession of them, and the reckoning still underwayView all →