International humanitarian law is the law that governs the conduct of participants during armed conflict. This branch of law aims to regulate the means and methods of warfare as well as to provide protections to those who do not, or who no longer, take part in the hostilities. It is one of the oldest branches of international law and one of enduring relevance today. This book provides an authoritative and practical overview of this important area of law. The book covers the foundations of international humanitarian law, including its sources, scope of application, and provides an overview of the classification of conflicts and domains of warfare. Chapters then deal with traditional issues that arise in the application of this body of law, such as the basic principles of the conduct of hostilities, the fundamental guarantees provided by this body of law, as well the law relating to weapons, detention, and specifically protected persons. The book also considers the implementation of this body of law, including through criminal prosecution for war crimes. Finally, it addresses the relationship between international humanitarian law and modern challenges relating to protection of the environment, human rights, and terrorism. The book targets professionals, as well as advanced students, with information and analysis of sufficient depth to enable them to perform their tasks with understanding and confidence. It also serves as a first port of call, a one stop shop, and a regular reference work for those interested in international humanitarian law.