As the gunshots that fatally wounded Archduke Franz Ferdinand and Countess Sophie of Austria resounded from Sarajevo across Europe to become the deafening roar of artillery on the Western Front in August 1914, Harvey Williams Cushing was the world's preeminent neurosurgeon and Gordon Morgan Holmes was arguably the foremost neurologist in the world. The 45-year-old Cushing, and Holmes just 38 years old, would strive to respond to the neurological challenges of World War I. They distinguished themselves amidst the redoubtable efforts of workers such as Walter Cannon, George Riddoch, Charles Sherrington, Henry Head, Victor Horsley, Walther Poppelreuter, and Robert Barany. Even the intense martial spirit of the time would be held in abeyance by the contributions of such men of science, as when the intercession of Prince Carl of Sweden secured the release of Barany from a Russian prisoner-of-war camp and allowed him to accept the 1916 Nobel Prize for his exposition of vestibular physiology. Such respite from the brutality of war was all too brief, and if we are to grasp the significance of the different approaches of Holmes and Cushing to the terrible problems of World War I, we must examine some of the harsh medical realities that they confronted in the "war to end all wars."