[Picture: Map of Sydney Cove published July 24, 1789]
In April 1789 a disease, thought to be smallpox, spread through the Eora people and surrounding groups, with the result that local Aborigines died in their thousands, and bodies could often be seen bobbing in the water in Sydney Harbour. Colonial historian and First Fleet officer Watkin Tench, whose accounts are primary sources about the early years of the colony, suggested that the epidemic may have been caused by Aborigines disturbing the grave of a French sailor who died shortly after arrival in Australia (supposedly of smallpox) and had been buried at Botany Bay. However, the very strict Aboriginal customs concerning graves and dead bodies make this unlikely in the extreme. Another intruiging possibility suggested by Tench was that one of the colony's physicians had reportedly brought a vial of smallpox-infected material with him from England, that he may have been experimentally inoculating of colonists and/or local Aboriginal people against the disease and that it spread into the Aboriginal population by this vector. However the fact that there was no smallpox in the settlement, and that the settlement had been totally isolated from the rest of the world for two years, makes it likely that the outbreak came from some other source, possibly from Darwin.
Whatever the actual cause, the results were catastrophic for the Eora people and their kin and by the early 1800s the Aboriginal population of the Sydney basin had been reduced to only 10 percent of the 1788 estimate.