The Mark I helmet, a design by Latvian-born British inventor John L. Brodie (b. Leopold Janno Braude), was the standard steel helmet used by the British Empire troops in WW1, as well as by the American and Portuguese forces. It protected soldiers’ heads from shrapnel bullets, shell fragments, and other flying debris on the battlefield. Brodie’s design using hardened manganese steel (the type A) entered service in the fall of 1915. It was criticized widely. The improved Mark I version entered service in May 1916 and was used by a number of armies up through the 1960s.