Anglo Saxons arrived at the British Isles in the 5th century and became the dominant power in England fairly quickly. They ruled over most of Britain for the next 6 centuries until they were ousted from power by the Normans in the 11th century. The military culture of the Anglo Saxons evolved from their Germanic origins and accepted influenced from the Celtic Britons.
A unique aspect of Anglo-Saxon warfare was that they used no cavalry in combat and fought on foot, even as late as the 11th century. In such situations, shields were the most vital part of Anglo Saxon armour and played a central role in battlefield combat.
Most Anglo Saxon shields were made from different types of wood, a material that was abundantly available in Britain. Ash, oak, maple, alder, willow and poplar wood were among the most commonly used types of wood in shield construction.
The basic design of an Anglo Saxon shield comprised of multiple wooden planks packed in a circular shape and held together using some adhesive material. In some cases, the wooden structure was then covered with an extra layer of leather to reinforce the shield and make it stronger. Richer Anglo-Saxons of the noble class would occasionally cover the wooden shield structure with a metal like bronze, making it a lot stronger.
In the absence of cavalry units, Anglo Saxon armies typically comprised of infantry-only troops. In the combat that ensued at battles involving these armies, Anglo Saxon shields played a central role. At the very beginning of the battle, both sides would draw themselves up into a defensive formation known shield wall.
As the name suggests, the shield wall comprised of Anglo Saxon warriors standing close to each other and holding their shields aloft in front so that they appeared like a continuous wall. The warriors would then throw their javelins from behind the shield wall and occasionally go beyond the wall for an open attack.
Later in the battle, shield walls on both sides typically inched closer until they crashed into each other and then it was a push-and-break contest between the two sides with spears used at close quarters.
Shields of many different sizes were used by the Anglo-Saxon although the shape of most of them was consistently circular. The shields ranged in diameter from 1 foot to 3 feet. It is probable that the smaller shields were used in skirmishes while larger shields were more effective during shield wall formations.
The thickness of the shields also ranged widely with most shields ranging in thickness between 5 mm and 13 mm. A notable feature of the design of Anglo-Saxon shields was a well-manufactured boss on the centre of the shield. The most common type of boss used on Anglo-Saxon shields was a carinated boss while a tall cone boss was also frequently used in early Anglo-Saxon shields. A piece of the shield was cut away at the position of the boss and the boss was then attached at the centre using multiple metal rivets.