Fourth Romat'ison was a Jem'Hadar soldier who served during the first month of the Dominion War. He served under First Teron'tokal and Vorta overseer Yelgrun, who commanded a patrol sent to monitor the activities of the USS Lambda Paz, which was dispatched to the Tong Beak Nebula to verify intelligence that a Jem'Hadar breeding facility was being built on a planetoid in the nebula. Romat'ison was named second-in-command by the time that same fleet of ships confronted the Federation Alliance in the Siege of Sector 21607 following the executions of Second Ulin'talag and Third Otan'irix for insubordination. Because Romat'ison was young and inexperienced, Yelgrun decided he would have to earn a promotion to the rank of Second once the battle was won.