This is a book that throws a new, baffling light on the subject of holy war. There are many studies on this phenomenon, based on historical, political, and sociological analyses; however, this book suggests a different angle, emphasizing the most specific and most determinant aspect of holy war: religion. This book is a journey in search of the "spirituality of war", a dimension which is a common heritage of nearly all cultures and religions. Through a wide outline on war spirituality from the Bible and the Quran, crusaders and mujahidins, samurais and Aztec priests, it argues that war can be seen as a way of liberation for oneself and for others, a way of mystical asceticism and introspection.