This book develops a sociologically informed theory of constitutionalism in the global realm, addressing both national and transnational forms of constitutional ordering. Poul F. Kjaer offers a sociological and historically informed analysis of the evolution of constitutionalism in the face of globalisation. The analysis contextualises on-going constitutional developments through the use of a long-term historical perspective, which is capable of highlighting the impact of deeper structural transformations unfolding within society.