A Mark 1 steel helmet with leather chin strap, the front of the helmet has an applied Royal Horse Guards cap badge on the front, with central GvR monogram; RHG has been painted in large black letters on the front. The interior has a leather lining.

This type of helmet derives from those designed by John Leopold Brodie in 1915. At the start of the First World War in 1914 the troops from most of the participating countries did not have sufficient head protection in order to protect from modern weapons. This type of steel helmet could withstand much more than the cloth or leather helmets previously used. They were introduced to British troops in 1915 and underwent various modifications over the years, but were still in use during the Second World War.

This example was worn by King George V on one of his visits to the Western Front.