Armor is protection against weaponry. Soldiers' body armor (usually made of metal or thick leather) has been employed since antiquity to prevent or reduce injury. Except for helmets(and occasionally bulletproof vests) body armor ceased to be used in European battle in the seventeenth century. Warships were first armored in the mid-nineteenth century, using metal plating to deflect small-arms fire. Vehicles acquired armor-plating during World War I. Armored vehicles include tanks, armored personnel carriers, and mechanized artillery.