Winston Churchill's career in the First World War is often characterized by his work at the Admiralty, by the advocacy of the tragic Dardanelles campaign, and the support of the landship, a prototype of the tank. Churchill's tenure at the Ministry of Munitions, from July 1917 to January 1919, has received little scholarly attention. This study examines the development of Churchill's strategic thought and administrative actions in the last years of the First World War. As Minister of Munitions, Churchill's greatest contribution to the war effort was his comprehensive approach to the supply and strategy of mechanical warfare, trench mortars, tanks, and airplanes. His penchant for details allowed him to offer technical and tactical appreciations that challenged traditional military thought. The Ministry of Munitions, under Churchill, became a vehicle for war direction.