The Raven's Valour was a Strike Cruiser in the Raven Guard Legion, during the Horus Heresy. As the Heresy began, the Raven's Valour was left behind with a small force of the Legion, led by Commander Branne Nev, to defend Deliverance while Corax led the Raven Guard to confront Horus on Isstvan V. Months later, Corax and the Legion had not returned, and so the Raven's Valour was part of a flotilla of ships that Nev led to the enemy held Isstvan System in search of the Primarch. When they neared Isstvan V, Nev dispatched the ships of the Therion Cohort to Isstvan IV to draw off Horus' forces, while the Battle Barge Avenger evacuated Corax and what remained of his Legion after the Dropsite Massacre. When the evacuation was completed, Corax ordered the Avenger, Raven's Valour and the Strike Cruiser Triumph, to each leave Isstvan V on different headings in order to confuse Horus' pursuing forces. The Raven's Valour and Triumph were both able to successfully escape from the System and returned to Deliverance.