Black Line
The Black Line is a notorious incident that occurred in 1830 on Tasmania, or Van Diemen's Land as it was then known. After many years of conflict between British colonists and Aboriginal known as the Black War, Lieutenant-Governor George Arthur called upon every able-bodied male colonist, convict or free, to form a human chain that then swept across the settled districts, moving south and east for several weeks in an attempt to corral the Aborigines on the Tasman Peninsula by closing off Eaglehawk Neck (the isthmus connecting the Tasman peninsula to the rest of the island).
The incident is commonly seen as a costly fiasco since few Aborigines were captured. However, it is also generally accepted that the incident shook the Aboriginal population so much that they were willing to accept the mediation of George Augustus Robinson and allow themselves to be removed to the Flinders Island settlement, where the population dwindled until repatriation to Tasmania in 1847. Marginalising them to Flinders Island did what the Black Line failed to do - ethnically cleanse the local Aboriginal population. As a direct result, of all the Australian regions, Tasmania has very few aborigines or preserved native culture of note.