The round shield is most often associated with Vikings but was used in many places and was used around the 8th to 11th century. This type of shield was made with a center handle which allows for a large amount of movement and offensive capability while still providing protection from projectiles and melee combat alike. The typical round shield of the period would have been made of wood sheets glued together and then covered in layers of linen, the edges then covered in a layer of rawhide. The thick hard leather in conjunction with the cloth facing prevents the shield from splitting and prevents blades that strike the edge from being easily retrieved. Our 30" across shields are made in this same fashion utilizing a cross grain canvas facing over birch wood with a stitched rawhide edge, in the center is a 14 gauge steel boss mounted with rivets and washers made in house for the authentic feel.
 
Similar shields in use can be seen here