Bishop, from Ultima Underworld II
Prior to Ultima Underworld II, Bishop got captured by the Goblins, who rule Tarna in the name of the Guardian. However, every attempt to get something out of him was futile, and they still feared him even as a prisoner. Bishop however became suspicious when one day a Blackrock Gem appeared in his cell, and six guards were sent to get it.
In Ultima Underworld II, the Avatar finally met Bishop, who already knew of Britannia's hero. He told the Avatar about his role as the resistance leader, and also revealed that there were people on other worlds where his name could open doors. He also talked about the Blackrock Gem, suggesting that Borne might have it now. The Avatar then gave Bishop a spare pair of Fraznium gauntlets, so that Bishop could make his escape through the force field, and return to fighting the Guardian's troops.
Bishop's name helped the Avatar gain help from the sorceress Altara on Killorn Keep and his escape was information wanted by the Xorinite Wisp. Bishop's silence about his plans prevented the wisps from gaining information that might be passed to the Guardian. Garg gave a letter from Bishop to the Avatar recommending they speak with Zoranthus.