<P> The island is believed to have been occupied by Aboriginals for 40,000 years before British colonisation . It is thought Tasmanian Aboriginals were separated from the mainland Aboriginal groups about 10,000 years ago when the sea rose to form Bass Strait . The Aboriginal population was estimated to have been between 3,000 and 7,000 at the time of colonisation , but was almost wiped out within 30 years by a combination of violent guerrilla conflict with settlers known as the `` Black War '' , intertribal conflict , and from the late 1820s , the spread of infectious diseases to which they had no immunity . The conflict , which peaked between 1825 and 1831 and led to more than three years of martial law , cost the lives of almost 1100 Aboriginals and settlers . The near - destruction of Tasmania 's Aboriginal population has been described by some historians as an act of genocide by the British . </P>
<P> The island is believed to have been occupied by Aboriginals for 40,000 years before British colonisation . It is thought Tasmanian Aboriginals were separated from the mainland Aboriginal groups about 10,000 years ago when the sea rose to form Bass Strait . The Aboriginal population was estimated to have been between 3,000 and 7,000 at the time of colonisation , but was almost wiped out within 30 years by a combination of violent guerrilla conflict with settlers known as the `` Black War '' , intertribal conflict , and from the late 1820s , the spread of infectious diseases to which they had no immunity . The conflict , which peaked between 1825 and 1831 and led to more than three years of martial law , cost the lives of almost 1100 Aboriginals and settlers . The near - destruction of Tasmania 's Aboriginal population has been described by some historians as an act of genocide by the British . </P>
when was tasmania cut off from the mainland
when was tasmania cut off from the mainland
10,000 years ago
10,000 years ago