Only in the last few years has the idea that Australia might well be thought of as an empire in its own right been floated. Previously, scholars tended to hedge their bets, using such terms as ‘proxy imperialism’ or ‘sub imperialism’, or perhaps simply ‘expansion’. In part, this tenuous approach derived from a previous generation’s scholarly focus on the historical problem of Australian national identity, which was then understood to be antithetical to empire. Yet, as new imperial histories and growing transnational and transcolonial historiographies show clearly, settler polities developed political cultures all their own, and with a variety of ideals animating contentious and unique debates in which ‘nationality’ and ‘empire’ could easily be complementary and even coterminous. Thus Australian settler cultures, ideals, and debates, while often treated as parts of a ‘British world’, deserve to be understood on their own terms. And, in their own words, many Australian settlers and later Commonwealth citizens ordered their political lives and visions of the future according to a unique settler idea of a transcolonial, cooperative project of empire – one that belonged to all white settlers equally, and one that demanded their allegiance as well.