The Lost Legions explores the cultural interactions between Indigenous peoples and European settlers. Paterson draws especially on archaeological evidence from central Australia, where European pastoralists found themselves in the heart of the territory of the Aborigine Arabana people. Paterson also considers other sources of information—such as oral histories, onomastics, and evidence of culture contact in the Americas and South Africa—to develop a broad understanding of what happens when such different civilizations encounter one another.