"An epidemic of smallpox among Aboriginal people around the infant colony of Sydney in 1789 puzzled the British, for there had been no cases on the ships of the First Fleet. Where, then, did the epidemic come from?

"As explorers moved further inland, they witnessed other epidemics of smallpox, notably in the late 1820s and early 1830s and again in the 1860s and 1870s. They also encountered many pockmarked survivors of early epidemics.

"In Invisible Invaders, Judy Campbell argues that epidemics of smallpox among Australian Aboriginals preceded European settlement. She believes they originated in regular visits to the northern coast of Australia by Macassan fishermen from southern Sulawesi and nearby islands. They were searching for trepang, for which there was a profitable market in China" (publisher).