Laws regulating armed conflict have existed for centuries, but the bulk of these provisions have been concerned with wars between states. Relatively little attention has been paid to the enormously important area of internal armed conflict. At a time when international armed conflicts are vastly outnumbered by domestic disputes, this book seeks to redress the balance through a comprehensive analysis of those rules which exist in international law to protect civilians during internal armed conflict. From regulations in the 19th and early 20th centuries according to the doctrine of recognition of belligerency, this book traces the subsequent development of international law by the Geneva Conventions and their additional Protocols, as well as through the more recent jurisprudence of the Yugoslav and Rwandan tribunals. The book also considers the application of human rights law during internal armed conflict, before assessing how effectively the applicable law is, and can be, enforced.