Dupre's Shield is a special shield, used by its namesake for many years. Strong magics are woven into it, ensuring superior protection while at the same time enhancing battle strength. However, as the name says, there is only one such shield, and it is the personal possession of Dupre, one of The Companions of the Avatar.
This Shield was for a long time in Dupre's possession, but was only first seen in Ultima VII Part Two, when he brought it to the Serpent Isle. Exchanged by a Teleport Storm with a Shield of Monitor, Luther used it to become a nasty bully in Monitor, until the Avatar defeated him in a sparring match. Afterwards, it stayed with Dupre until his death.
It is unknown what happened to the shield after Dupre's passing.