A male human serving the Imperial Navy as an admiral, Durril participated in the Batonn insurgency. During the Battle of Scrim Island, Admiral Durril was in command of the Imperial Star Destroyer known as the Judicator, which was part of the One Oh Third Task Force.
The mission of Admiral Durril was to eliminate the Batonn insurgents who had taken control of Scrim Island. His approach involved what he termed the "Standard Siege Tactic." After negotiations that were considered unsuccessful, he gave the order for all ships to fire upon the shield generator that protected the Island. This bombardment had no impact on the shield generator's strength. As Durril's attention was focused on the shield's center, the western and southern edges began to retract, and two ion cannons launched attacks against the Judicator. He then instructed his escorting frigates to target the shield's edge, but by the time they initiated their attack, the shield had already expanded, covering them once more. Subsequently, the shield contracted in the north, resulting in additional ion shots, while the One Oh Third Task Force engaged the western and southern emplacements, which remained shielded. As Durril's attention shifted to the North, eight freighters managed to escape from beneath the shield. Seven of these ships headed to different continents, while one returned to space and subsequently executed a jump to hyperspace.
Durril's efforts during the Battle of Scrim Island ended in a significant defeat, as he was unable to retake Scrim Island. As a result, he was compelled to undergo repairs and was reassigned, paving the way for Admiral Thrawn to take over the mission.
Durril's initial appearance occurred in the 2017 novel titled Thrawn, authored by Timothy Zahn.