The Truth was a warship in the Imperial Fists Legion during the Horus Heresy. It was part of the Retribution Fleet sent by the Primarch Rogal Dorn to confront Horus when the Heresy began. However, due to severe Warp Storms, the Fleet was left stranded in the Phall System and the Truth later fought the Iron Warriors Legion, during the Battle of Phall. During the battle it worked together with the Imperial Fists' warships the Halcyon and Unity, to destroy the Iron Warriors Battle Cruiser Dominator; however, as they turned away from its wreckage they came under attack from the Battle Barge Iron Blood. The Iron Blood's attack completely destroyed the Unity and before the Truth could react, the Battle Barge fired upon it again and destroyed the warship as well.