Chief Retwin was a Human male from the planet Ralltiir. A former Imperial sympathizer who worked for his homeworld's defense forces, Retwin joined the Empire after the Imperial subjugation of Ralltiir shortly before the Battle of Yavin. Retwin later served aboard the Super Star Destroyer Executor, the personal flagship of the Dark Lord Darth Vader, during the Imperial subjugation of Bespin's Cloud City in 3 ABY.