Over the past 150 years, the International Committee of the Red Cross (ICRC) has been one of the main drivers of progressive development in international humanitarian law, whilst assuming various roles in the humanization of the laws of war. With select contributions from international experts, this book critically assesses the ICRC's unique influence in international norm creation. It provides a detailed analysis of the workings of the International Red Cross, Red Crescent Movement and ICRC by addressing the milestone achievements as well as the failures, shortcomings and controversies over time. Crucially, the contributions highlight the lessons to be learnt for future challenges in the development of international humanitarian law. This book will be of particular interest to scholars and students of international law, but also to practitioners working in the field of international humanitarian law at both governmental and non-governmental organizations.