The Vengeful Spirit was an ancient Gloriana-class Battleship, adapted to a variant of the Scylla Pattern, that served as the flagship of the Warmaster Horus and the XVI Space Marine Legion. The Vengeful Spirit formed the core of the Luna Wolves (later called the Sons of Horus) Legion's campaigns during the Great Crusade and the Horus Heresy. It was upon the Vengeful Spirit that the final conflict between Horus and the Emperor of Mankind played out in the final hours of the Heresy's climactic Battle of Terra which would leave Horus dead and the Emperor mortally wounded, forever after interred within the life-support mechanisms of the Golden Throne.
In the early days of the galaxy-spanning campaign known as the Great Crusade, the Emperor and the only one of his sons to have been recovered, the Primarch Horus, forged the initial expansion of the newborn Imperium of Man. The Emperor of Mankind still walked among humanity, and vast Legions of Space Marines sallied forth to take possession of the galaxy, subduing all that stood before them and exterminating any xenos encountered to make way for His divine Manifest Destiny. When the Adeptus Mechanicus first swore their fealty to the Emperor as their Omnissiah following the Treaty of Mars, many wondrous and terrible creations did the Adepts of Mars construct to reunite all the disparate peoples of Mankind into one unified Imperium. Among these vessels was a new kind of warship, one of unbelievably vast dimensions equipped with all the firepower of a Battleship but capable of transporting and delivering vast numbers of men and materiel directly to the battlefield. This new type of warship served as the chariots that carried forth the Emperor and his Primarchs to conquer the galaxy. Designated a Battle Barge, no other starship type came to be as feared and respected as these, and just their arrival would often result in the quick surrender of a contested star system.
A heavy ingot of fashioned iron, the Vegeful Spirit radiated quiet power. Even from a distance one could see hundreds of gun turrets and the slender rods of massive accelerator cannons that were twice the length of most Imperial Battleships themselves. The prow of Horus' flagship displayed a massive golden ring which bisected a slim ellipse. This was the eye of the Warmaster himself, unblinking and open to see all that transpired. From the Vengeful Spirit's Strategium, and later the Lupercal's Court, a throne room centred upon the voidship's massive command deck, Horus would coordinate the military and diplomatic efforts of the 63rd Expeditionary Fleet of the Great Crusade, and countless thousands of Imperial personnel from a multitude of Imperial organisations who lived and worked on board. Additionally, because the vessel was so old, one of the first warships built for the Imperium by the Mechanicus of Mars following the alliance between the newborn Imperium of Man and the Priesthood of Mars in the late 30th Millennium, the core of the ship was a rotting, empty labyrinth of filth and vermin. It was there, in the bowels of the Vengeful Spirit, that the Chaos-tainted Word Bearers First Chaplain Erebus schemed to corrupt Horus to Chaos on the command of his new masters within the Immaterium. Erebus hid the Chaos-tained blade known as the Kinebrach Anathame that would be used to mortally wound Horus on the feral moon of the world of Davin within this area of the warship after he stole the weapon from the Hall of Devices museum on the Interex world of Xenobia. The core of the Vengeful Spirit is also where Erebus would eventually hold the ritualistic ceremonies of dark worship and human sacrifices that were required for Horus to communicate with the Ruinous Powers of the Warp he later called allies. Over time, and especially after the Istvaan III Atrocity, the Venegeful Spirit became less of a warship and more of a temple to the Dark Gods of Chaos whom Horus came to revere in his quest for domination over the Imperium of Man.
The Sons of Horus took part in many of the campaigns of the Horus Heresy, from the betrayal at the Drop Site Massacre of Istvaan V right through to the Siege of the Emperor's Palace. It was in the all-consuming fires of the Horus Heresy that Battle Barges proved themselves as both the bane and savior of Mankind. Countless worlds were reduced to rubble and seas of radioactive glass under the withering fire of its many rows of weapon batteries, and countless numbers of these vessels were lost defending Loyalist worlds against the host of the Betrayer's warfleets. In fact, it was aboard the Vengeful Spirit, the flagship of Horus throughout the conflict, that the final climactic battle of wills took place between the Emperor and his once favoured son who have become the most foul Arch-Traitor in Mankind's history. Though the Emperor was mortally wounded, Horus was slain, and this one act spelled defeat for the Forces of Chaos as the battle for Terra was won and Humanity's once-bright future was shattered beyond repair.
Following the Horus Heresy, Abaddon the Despoiler, the former First Captain of the Sons of Horus and the new Warmaster of Chaos Undivided and commander of the renamed Black Legion, claimed the Vengeful Spirit as his own flagship. It still forms the heart of the Black Legion's fleet to this day. Nearly all of the titanic warships of the Gloriana-class were lost or destroyed during and immediately after the Horus Heresy and subsequent reorganisation of the remaining Loyalist Space Marine Legions during the Second Founding into the many Chapters of the Adeptus Astartes that thereafter existed for millennia. Few of these vessels are still confirmed to exist, such as the Harbinger of Doom of the Black Legion and the Stonebreaker of the Iron Warriors, though others may still ply the unassailable reaches of the Maelstrom and the Eye of Terror. Though exceedingly rare, these vessels still rightfully command deep respect and fear.
- Battlefleet Gothic 2010 Compendium, pp. 111-112
- Horus Heresy: Collected Visions
- False Gods (Novel) by Graham McNeill
- Galaxy In Flames (Novel) by Ben Counter
- Horus Rising (Novel) by Dan Abnett
- Vengeful Spirit (Novel) by Graham McNeill
- Soul Hunter (Novel) by Aaron Dembski-Bowden
- The Talon of Horus (Novel) by Aaron Dembski-Bowden