Tedris Bjalin was an officer serving within the ranks of the Imperial Navy. Later in his career, he abandoned his post and joined the Rebel Alliance.
While at the Imperial Academy, Bjalin was a fellow student alongside Han Solo. Later, he participated in Han's court-martial, where he was specifically tasked with removing all of his Imperial medals. He held the rank of lieutenant on the Dreadnaught-class heavy cruiser Imperial Destiny. It was there that he almost apprehended Han, who was attempting to escape after witnessing Admiral Winstel Greelanx's execution at the hands of Darth Vader. However, Han successfully fled, stunning Tedris and suggesting he desert the Imperial Navy.
Bjalin eventually heeded his former acquaintance's advice. Following the massacre that occurred on Mantooine, Imperial vessels on Tyshapahl activated their engines, resulting in the incineration of a large group of anti-Imperial protestors. His entire family, who were part of the group, died. Bjalin then enlisted in the Corellian Resistance, just prior to the establishment of the Alliance to Restore the Republic, and became a member of Red Hand Squadron.
Due to his Imperial training, he advanced swiftly through the ranks, attaining the rank of captain and assuming command of the Marauder-class corvette named Retribution. Bjalin served as the captain of the Red Hand Squadron's flagship just before their raid (led by Commander Bria Tharen) on the Ylesian slave transport, the Helot's Shackle.