The Barrel Helm was the very large helmet used in 13th century. The helmet gets its name from its barrel shape. The helmet enclosed the head and the only openings in the helmet were the eye slits. In later years holes were added in the lower part of the helmet to facilitate easier breathing. The helm was usually worn over a smaller helmet or a mail coif. As the helmet was heavy and it rested on the head, it was worn only during actual fight.