Shields were one of the earliest and most important pieces of defensive armour through most of the medieval period. They were used in classical antiquity, so European warriors in the early medieval period knew how to make strong shields.
During the course of the medieval era, the design of battlefield shields evolved significantly. Earlier shields were made mostly from wood and were effective against rudimentary weapons such as early swords and axes.
As weapons evolved, so did the shields and by the high middle ages, shields were more sophisticated design and construction were being used on European battlefields.
The design and construction of shields evolved significantly during the medieval period. Early medieval shields were entirely wooden while later shields featured significant amounts of metal for reinforcement. Similarly, early medieval shields were circular in shape while new shapes were invented towards the High Middle Ages.
Early medieval period was a time when metal was scarce and expensive. Consequently, it was only used in weapons while shields were made almost entirely from wood.
The most common type of shield used during this period was the round shield of rather small size which was made from planks of wood glued together and bound for strength using strips of metal. The use of leather was common as a way of reinforcing the metal surface of the shield.
By the High medieval period, shields had evolved to a new level of sophistication. By this time, new weapons were used on European battlefields and this necessitated the use of better-designed and sturdier shields. The most notable types of shields that came to be used during this period were the kite shield and the heater shield.
The kite shield, as its name suggests, was kite-like in shape and was significantly large in size, meant to guard not just the upper body of a soldier but also the legs.
This type of shield was popularised by the Normans as they launched attacks into different parts of Western Europe during the 10th and 11th centuries.
The kite shield had the vital advantage of letting a knight shield an entire side of his body which was significant in close-combat situations. Due to its large size, the kite shield was heavier that the conventional round shield. To carry the shield, enarmes were located at the back of a kite shield to allow the bearer to hold on to the shield with a firm grasp.
As the use of body armour became popular in European armies, the significance of shields diminished at the same time. Towards the 13th century, body armour had become solid enough to withstand most battlefield weapons, although a shield still had its advantages.
The result was that although shields continued to be used in battles, they evolved into a new type later called the heater shield. A heater shield was essentially similar to a kite shield in shape but much smaller in size.
The size of a heater shield made it adequate for only upper-body defence. This type of shield eventually came to be a part of the heraldic achievement.