Some mounted machine guns and artillery pieces are equipped with metal armor plates to protect the gunners from small arms fire and shrapnel from explosions.
Israeli military analysts began urging the use of gun shields, pointing to the grave risk to soldiers exposed to fire from automatic weapons.
The United States Armed Forces began using gun shields in the early 21st century during the wars in Iraq and Afghanistan.
There are 46 surviving examples originally from the armoury of Henry VIII at the Palace of Westminster, the Tower of London and other Royal sites.
They have been thought to be Italian in origin, as they were offered to Henry VIII in a letter of 1544 from a painter of Ravenna named Giovanbattista.