This is the third best shield. It may be seen on Emperor Kruzak's treasure room, in Kazordoon, and also in the Maze of Lost Soul's treasure. It's known that the first Great Shield was owned by Cressir on Antica.
This shield was dropped by Dragon Lords, during some period of time long time ago. Looting this was harder than looting a Dragon Scale Mail. Back in that times there was only three Dragon Lord spawns, the one in the Plains of Havoc, the one in Thais, and the one in Deeper Fibula. Also Dragon Lords were the hardest monster back then, and the highest levels were around 50. After some time CipSoft removed the shield from the Dragon Lord loot, so it's not an item you would see everyday. It's part of Full Set. Now this shield is dropped by Massacre, the Juggernaut boss as well as Ferumbras, Ghazbaran and Morgaroth. The guild Division of Honour (from Guardia) looted the shield in a Pits of Inferno Quest service.