Pillage means theft during war. Although the prohibition against pillage dates to antiquity, pillaging is a modern war crime that can be enforced before international and domestic criminal courts. Following World War II, several businessmen were convicted for the pillage of natural resources. And yet modern commercial actors are seldom held accountable for their role in the illegal exploitation of natural resources from modern conflict zones, even though pillage is prosecuted as a matter of course in other contexts. This book offers a doctrinal road-map of the law governing pillage as applied to the illegal exploitation of natural resources by corporations and their officers. The text traces the evolution of the prohibition against pillage from its earliest forms through the Nuremberg trials to today’s national laws, international treaties and case law from international courts. In doing so, it provides a long-awaited blueprint for prosecuting corporate plunder of resource wealth during war. This also holds great relevance as a response to conflict financing. Since the end of the Cold War, the illegal exploitation of natural resources has become a prevalent means of financing conflict. In countries including Angola, the Democratic Republic of the Congo, East Timor, Iraq, Liberia, Myanmar, and Sierra Leone, the illicit trade in natural resources has not only created incentives for violence, but has also furnished warring parties with the finances necessary to sustain some of the most brutal hostilities in recent history. This text marks the beginnings of a coherent legal response.