"To explain Rome's rise under the Republic the great Theodor Mommsen in the nineteenth century originated a concept of defensive imperialism (an empire dragged ever outwards as it reacts to threat after threat) shading off into a search for natural, defensible boundaries. This concept proved highly agreeable to a colonial world and found influential proponents in the early twentieth century in Frank and Holleaux. It could confidently be wheeled out as late as the early 1970s. In his book War and Imperialism in Republican Rome 327–70 BC (Oxford, 1979) W.V. Harris effectively demolished, at least for our post-colonial age, the idea of defensive imperialism. Instead he replaced it with the concept of Rome as an aggressive polity; driven to foreign wars, and thus often to expansion, by the conscious desire of individual senators (the élite of élites) for military glory and financial gain."