One of the primary elements of the armour of a knight was shield. They used shields to block strikes and stop the missile attacks. Oval shields were used during the Dark Ages which were made of wooden boards and they were roughly half an inch thick. Quite short before the 11th century, oval shield was lenghtened to cover the left knee of the mounted warrior. They used triangular shield during the 13th and the first half of the 14th century. Around 1350, square like shields appeared which had a hatch to place the couched lance.