Treaty of Neuilly-sur-Seine
During World War I Bulgarian soldiers were equipped with the German Stahlhelm M1916, which remained in service up to the end of the 1930s. The restrictions imposed on the Bulgarian Army by the Treaty of Neuilly-sur-Seine of 1919 were overcome in the mid-1930s and in 1935 the High Command ordered the design of a new army helmet. At the end of 1935 the prototype was ready and subsequently approved in 1936.