This article systematically reviews how a large number of states relate to their diasporas. It shows how states constitute various extra-territorial groups as members of a loyal diaspora, through a diverse range of institutions and practices. The article distinguishes two types of diaspora mechanism: one which cultivates and recognizes diaspora communities, and another which draws them into reciprocal ties with their homeland. The article demonstrates that, contrary to the common wisdom, it is normal for states to have a variety of such mechanisms protruding beyond their borders and impacting on a variety of extra-territorial groups. It is useful to view these institutions and practices collectively as "the emigration state". The article argues that the emigration state has been overlooked by what John Agnew calls "the modern geopolitical imagination", in which territorial nation-state units, locked into competition at a fixed international scale, are thought of as the highest form of political organization. Â© 2008 Elsevier Ltd. All rights reserved.