Protective clothing that can shield the wearer from weapons and projectiles. By extension, armour is also protective covering for animals, vehicles, and so on. Prehistoric warriors used leather hides and helmets. Chinese warriors used rhinoceros skin in the 11th century BC, and Greek infantry wore thick, multilayered metal-and-linen cuirasses (armour covering the body from neck to waist) in the 5th century BC. Shirts of chain mail were worn throughout the Roman Empire, and mail was the chief armour of western Europe until the 14th century. Ancient Greeks and Romans used armour made of rigid metal plates, which reappeared in Europe around the 13th century. Plate armour dominated European design until the 17th century, when firearms began to make it obsolete. It began to disappear in the 18th century, but the helmet reappeared in World War I and became standard equipment. Modern body armour (the bulletproof vest) covers the chest and sometimes the groin; it is a flexible garment reinforced with steel plates, fibreglass, boron carbide, or multiple layers of synthetic fabric such as Kevlar.