The Gothic Sector's most important attribute was that it was the location of the six known Blackstone Fortresses, the powerful xenos artefacts originally created by the Old Ones to serve as weapons against the C'tan during the War in Heaven over 65 million standard years ago. When Mankind re-discovered the worlds of the Gothic Sector during the Great Crusade, the Imperium found the Blackstone Fortresses and eventually transformed them into Imperial naval bases. During the Gothic War, the capture of these fortresses would become Abaddon's prime objective and he would manage to wrest control over three of the six known to exist. He used their powerful xenos technology to strip one planet of its atmosphere and transform another star into a supernova that destroyed its surrounding planetary sy