This article focuses on the internationalization of constitutional law. It discusses major trends in the internationalization of constitutional law, including the incorporation of international human rights treaties into constitutions, convergence, and comparativism of national constitutions, and constitutional devolution or treaty-becoming constitutions. Next it makes inquiries into the driving forces that push the development of constitutions across and beyond their borders. It argues that the current internationalization of constitutional law results primarily from the expansion of a global market, the triumph of rights-based discourse, and, most importantly, the emergence of transnational networks by governments, non-governmental organizations, and technocrats or professionals.