Terra nullius is a Latin expression meaning "empty land" or "no man's land". The term refers to an 17th century legal concept that permitted European colonial powers to assume control of land that was unclaimed (at least by each other). England relied on this principle to claim possession of the Australian continent.
However, Australia was not really empty because there were a native people present, the Australian Aborigines. Yet it is unlikely that the English authorities of the 18th century would have given such a limited interpretation to terra nullius. Rather than implying mere emptiness, terra nullius was likely to have been more broadly constructed as an absence of civilised society. For example, the English common law of the time allowed for the legal settlement of "uninhabited or barbarous country". Although Australia was clearly not empty land, the presence of scattered and nomadic Aboriginal groups would have been widely perceived, through European eyes of the time, as evidence of a barbarous country and thus no legal impediment to settlement.
The concept of terra nullius became a major political and legal issue in Australia when, during a controversial Aboriginal rights case known as Mabo, the Australian High Court invalidated the concept.
