Hulton Archive / Getty Images We warn readers that the content of this study is confronting and may be distressing. In April 1789, the first smallpox epidemic among Aboriginal people in the Sydney region began, just 16 months after Europeans arrived on the First Fleet. Little is known of the true scale of the epidemic, and historians have sometimes argued it was not caused by the newcomers. In new research published in Nature Human Behaviour, we used modelling of smallpox transmission and the co