Weight: 0.2-0.5 kg each
The most vulnerable part of the leg in medieval battle was the knee. It is a vital area and easily damaged by blows struck with clubs, axes and swords. It is also very exposed, whether on foot or on horseback.
One of the earliest pieces of plate armour to appear in the Middle Ages was the poleyn - a solid, rounded knee plate worn over the other leg armour. Early poleyns were probably made out of hardened leather, but metal ones could not have been far behind.
Early poleyns were attached to the mail chausses and sometimes also strapped around the back of the leg. When worn over gamboised cuisses, they probably were often sewn, strapped or riveted onto the padded material underneath.