13th Black Crusade - 13th Black Crusade: The 13th Black Crusade of Abaddon the Despoiler that began in ca. 999.M41 resulted in the largest clash between Imperial and Chaos forces seen in the Milky Way Galaxy since the Horus Heresy ten thousand Terran years before.Abaddon raised the greatest army in service to the Chaos Gods since the time of Horus, and intended to bring an end to the Long War by driving on Terra, slaying the Emperor of Mankind upon His Golden Throne and at last completing the task the Traitor Legions had begun millennia before.The campaign began with a massive assault by the forces of Chaos out of the Eye of Terror into the sectors of the Segmentum Obscurus directly adjacent to the Cadian Gate. Fighting erupted on dozens, if not hundreds, of worlds within this region of the galaxy, with the ultimate objective of Chaos the seizure of the Cadia System and the Fortress World of Cadia at its heart.This victory would remove the last major bastion preventing Abaddon from unleashing his full force upon the Imperium of Man's defences and assaulting Terra for the second time in ten thousand standard years.The forward elements of the Black Fleet of Abaddon were ultimately forced to retreat from the Cadia System by the combined forces of the Imperial Navy and the Necrons. With the withdrawal of the Chaos warfleet, the Imperial defenders of Cadia, led by its new Lord Castellan Ursarkar E. Creed, were able to defeat the remaining servants of the Ruinous Powers who had made planetfall in the initial assault on the Fortress World.But this victory proved to be no more than a brief respite. Abaddon launched a second, far larger assault on the Cadian Gate that unleashed the full daemonic fury of the Eye of Terror directly upon an already-battered Cadia.Though the arrival of some unexpected Imperial reinforcements prevented Abaddon from personally sealing his victory by crushing Cadia's defenders, and led to the destruction of the Blackstone Fortress Will of Eternity, the Despoiler unleashed a brutal contingency plan.He had the massive fragments of the Will of Eternity hurled from orbit like an artificial asteroid onto the surface of Cadia. The strike destroyed what remained of Cadia's faltering defences and the network of Necron-built Cadian Pylons that had long prevented the Eye of Terror from naturally expanding into the Cadian Gate.Within only solar hours, most of Cadia was in the process of being consumed by the Immaterium when the tectonic instability caused by the impact of the Blackstone Fortress finally caused Cadia to tear itself apart.By that time, the few surviving Imperial forces had evacuated the planet, harried by the ships of the Black Fleet. The 13th Black Crusade had been a triumph for the servants of the Dark Gods, and the Eye of Terror began to slowly expand without limit, opening Abaddon the Despoiler's coveted Crimson Path to Terra and eventually becoming a part of the newborn Great Rift.Yet a handful of Imperial heroes had successfully escaped the fall of Cadia with the aid of the newborn Aeldari faction known as the Ynnari through a Webway gate found on the ice moon of Klaisus in the Cadian System.Together, these Imperials -- the so-called Celestinian Crusade -- would forge an uneasy alliance with the xenos that would offer a new hope for the servants of the Emperor in their fight against the waxing power of the Archenemy -- the resurrection of the Primarch Roboute Guilliman.