According to the historian Geoffrey Blainey, in Australia during the colonial period:In a thousand isolated places there were occasional shootings and spearings. Even worse, smallpox, measles, influenza and other new diseases swept from one Aboriginal camp to another... The main conqueror of Aborigines was to be disease and its ally, demoralisation.Henry Reynolds points out that government officials and ordinary settlers in the eighteenth and nineteenth centuries frequently used words such as "invasion" and "warfare" to describe their presence and relations with Aboriginal Australians. Reynolds argues that armed resistance by Aboriginal people to white encroachments amounted to guerrilla warfare, beginning in the eighteenth century and continuing into the early twentieth. In the early years of colonisation, David Collins, the senior legal officer in the Sydney settlement, wrote of the local Aboriginal people:While they entertain the idea of our having dispossessed them of their residences, they must always consider us as enemies; and upon this principle they [have] made a point of attacking the white people whenever opportunity and safety concurred.In 1847, Western Australian barrister E.W. Landor stated: "We have seized upon the country, and shot down the inhabitants, until the survivors have found it expedient to submit to our rule. We have acted as Julius Caesar did when he took possession of Britain." In most cases, Reynolds argues, Aboriginal people initially resisted British presence. In a letter to the Launceston Advertiser in 1831, a settler wrote:We are at war with them: they look upon us as enemies – as invaders – as oppressors and persecutors – they resist our invasion. They have never been subdued, therefore they are not rebellious subjects, but an injured nation, defending in their own way, their rightful possessions which have been torn from them by force.Reynolds quotes numerous writings by settlers who, in the first half of the nineteenth century, described themselves as living in fear due to attacks by Aboriginal people determined to kill them or drive them off their lands. He argues that Aboriginal resistance was, in some cases at least, temporarily effective; the killings of men, sheep and cattle, and burning of white homes and crops, drove some settlers to ruin.
