This innovative textbook provides an introduction into comparative constitutional law to undergraduate and graduate students. Combining a clear and practical explanation of the topics with scientific knowledge, the textbook analyzes the origins and the development of constitutional law in the Western world, as well as the structure and transformations of constitutional law, up to the present day. It also examines the theoretical roots and the historical premises of constitutionalism, and explores the foundation of constitutional law in Western countries since the Age of Revolutions and the 19th Century, underlining the different constitutional traditions. Furthermore, the textbook describes the transformations of constitutional law brought about by the transition toward pluralistic societies, and analyzes the political and legal features of constitutional democracies, taking into consideration the lessons learned in several constitutional environments in contemporary states. It also discusses the global expansion of the pattern of Western constitutionalism and the contemporary challenges in the age of globalization, focusing on the development of a European constitutional space.