Brownlee's 'Principles of Public International Law' has been shaping the study and application of international law for over 50 years. Serving as a single-volume introduction to the field as a whole, the book seeks to present international law as a system that is based on, and helps structure, relations among states and other entities at the international level. Authored by James Crawford, the ninth edition further secures the work as the essential international law text for students and practitioners.