Jerel Tremok entered the Imperial academy on Carida the first chance he got, and graduated with honors. He became a decorated officer early in his career, achieving the rank of General prior to the Battle of Yavin. Impressed, the Emperor relocated Tremok to a more Special Forces-oriented line of duty, and he became well notorious for his lethal methods and die-hard attitude toward defending the Empire.
Later, when the Empire collapsed with the Death of the Emperor and Darth Vader, Tremok took his unit and went renegade, securing a small base on Naboo. There, they remained, fighting Rebels who attempted to reclaim the world in favor of their New Republic, until he was found by Keldon Tyfus and offered to work for him in creating the Shadow Imperium. After reviewing the philosophy behind the Imperium's conception, Tremok saw this as an opportunity to assist in the recreation of Palpatine's Empire, and so he accepted.
He became the Surface Marshal for the Shadow Imperium's Armed Forces, and served Tyfus with fierce loyalty. Tremok continued to conduct his duties through numerous victories, and became a key figure in the Tingel Arm Sieges campaign.