Building on the recent initiative to truly globalize the field of international relations this book provides an innovative interrogation of regionalism. The book applies a globalizing framework to the study of regional worlds in order to move beyond the traditional conception of regionalism which views regions as competing blocs dominated by great powers. Bringing together a wide range of case studies the book shows that regions are instead dynamic configurations of social and political identities in which a variety of actors including the less powerful interact and partake in regionalization processes and have done so through the centuries.