The Black War was prompted by the rapid spread of British settlers and agricultural livestock throughout areas of Tasmania that had been traditional Aboriginal hunting grounds. Historian Nicholas Clements has described the Aboriginal violence as a resistance movement—the use of force against an invading or occupying enemy. He said the Aboriginal attacks were motivated by revenge for European atrocities and the widespread kidnapping, rape and murder of Aboriginal women and girls by convicts, settlers and soldiers, but particularly from the late 1820s the Aboriginal people were also driven by hunger to plunder settlers' homes for food as their hunting grounds shrank, native game disappeared and the dangers of hunting on open ground grew.[11] European violence, meanwhile, was motivated by mounting terror of Aboriginal attacks and a conviction that extermination of the Aboriginal population was the only means by which peace could be secured.