Isval was a Twi'lek female ex-slave who was a member of the Free Ryloth movement during the reign of the Galactic Empire. She was a lieutenant of Cham Syndulla, the movement's leader and military commander. Isval had a deep hatred for the Galactic Empire and took part in Cham's plot to assassinate Emperor Palpatine and Darth Vader. Following an arduous hunt, Isval and her fellow Free Ryloth fighters closed in on the Emperor and Lord Vader at a remote village. However, the Free Ryloth forces were routed by Imperial reinforcements led by Moff Delian Mors. Isval allowed herself to be captured so that Cham could escape. Following the battle, Isval was beheaded by Darth Vader after a brief exchange with the Emperor.