The term French Military Caps refers to Kepis, which are five-letter caps that were originally worn by the French military in the 19th century. The Kepi was a popular headgear for French soldiers during the Franco-Prussian War and World War I, and it is still used today by some French military units. The Kepi is a stiff, peaked cap with a flat top and a visor, and it is usually made of wool or cotton.