In more than ten books and numerous academic articles Reynolds has explained the high level of violence and conflict involved in the colonisation of Australia, and the Aboriginal resistance to numerous massacres of indigenous people. Reynolds, and other historians, estimate that up to 3,000 Europeans and at least 20,000 Aboriginal Australians were killed directly in the frontier violence, and many more Aborigines died indirectly through the introduction of European diseases and starvation caused by being forced from their productive tribal lands.