Colonel Lionel Pendergast served as a commanding officer of the United States Air Force Vessel Prometheus.
When Goa'uld System Lords proposed a treaty with Earth and negotiations broke down, a Goa'uld attack force was sent toward Earth, and the Prometheus was launched to defend the planet. However, the Goa'uld ships were eliminated by Ba'al, and the attack force never arrived.
Colonel Pendergast also commanded the Prometheus during the mission to locate and intercept the alkesh in Earth's orbit that was being used as a base of operations by the Trust. He succeeded in rescuing SG-1 from the ship and recovering the stolen stargate before the alkesh escaped into hyperspace. When members of the Trust were compromised by the Goa'uld and the alkesh returned to Earth, the Prometheus was launched once again under the command of Colonel Pendergast. Prometheus engaged the Goa'uld alkesh in battle and destroyed it.
As SG-1 faced the attempt by the Ori to establish a beachhead in this galaxy, Colonel Pendergast commanded the Prometheus during the mission to Kallana, where the Ori supergate was destroyed. When Ba'al attempted to establish a presence on Earth, Pendergast confronted Gerak's mothership near Earth's orbit, and he thwarted Ba'al's threat to blow up the Halcyon Tower if his demands were not met by beaming the tower into space where it detonated harmlessly.
During the mission to Tegalus, Prometheus attempted to disable Rand's Ori satellite weapon, however the ship came under attack by the satellite and was critically damaged. With weapons and shields inoperable, Pendergast attempted to negotiate a surrender, but the president of Rand ordered the ship's destruction. As Rand prepared to fire the satellite again, Pendergast ordered his crew to evacuate to Caledonia on the planet's surface. He remained aboard the Prometheus, desperately trying to bring the ship's systems back online, but when the satellite fired, Prometheus was destroyed, and Colonel Pendergast was killed. Of his crew of 115, only 76 survived.
Portrayed by: Barclay Hope