This book offers an answer to the question: what is public law? It suggests that an adequate explanation can only be given once public law is recognized to be an autonomous discipline, with its own distinctive methods and tasks. Martin Loughlin defends this claim by identifying the conceptual foundations of the public law in governing, politics, representation, sovereignty, constituent power, and rights. By explicating these basic elements of the subject, he seeks not only to lay bare its method but also to present a novel account of the idea of public law.