By the turn of the 20th century, localization of function in the cerebral cortex of the brain had advanced considerably, but a relatively vague idea only existed that human vision was represented in the vicinity of the calcarine cortex. World War I produced a large number of isolated missile wounds of the brain. Their study yielded a complete topographical mapping of the visual field in the primary cortical vision center, and is a basis of our modern interpretation of visual fields. This map has been recently modified by MRI studies to show that the magnification of the central retinal projection onto the cerebral cortex to be even greater than previously thought. Many names are associated with the story of how war led to this knowledge. This essay refers to Harvey Cushing, William Osler, Tatsui Inouye, and most particularly to the career and contributions of the British neurologist Gordon Holmes.