Gryphonne IV is a Dead World that was once an Imperial Forge World located in the Shiola Sub-sector of the Segmentum Tempestus' Alduin Sector. Gryphonne IV was the homeworld of the Titan Legio Gryphonicus and some of the fiercest and most skilled Skitarii Legions in the galaxy. Gryphonne IV was known to be one of the most well-defended worlds in the Segmentum Tempestus, which made its destruction all the more shocking. Gryphonne IV was one of the few Adeptus Mechanicus Forge Worlds that produced in significant quantities the less common Leman Russ main battle tank variant known as the Conqueror for the Imperial Guard. The designs for this Leman Russ variant were originally discovered on Gryphonne V. Following the loss of the Forge World of Tigrus, Gryphonne IV was also (with Stygies VIII) one of two Forge Worlds capable of producing versions of the Leman Russ Vanquisher main battle tank. Its last Imperial Planetary Governor was Fabricator-General Darius Hugh. Gryphonne IV was attacked and consumed by the Tyranid Hive Fleet Leviathan soon after its emergence into the galaxy in 997.M41, severely disrupting Imperial industry and supply in that part of the galaxy.
Gryphonne IV, the world of the Legio Gryphonicus's founding, located in the Segmentum Tempestus, was known to have been a seat of technological might according to ancient myths predating the Age of Strife, and so formed one of the earliest attempts of the Martian Mechanicum to reach out into the darkness during the Age of Strife. While many such missions resulted in failure and many of the Mechanicum Arks were sundered or lost without trace, doomed before the Emperor's intervention in the creation of the Navis Nobilite, the expedition to Gryphonne IV met with great success. This was likely a process of conquest over what local inhabitants remained rather than colonisation on the Mechanicum's part, although the truth of this matter has long since been sealed and forgotten by the Imperium. What is known is that after the founding of the Forge World of Gryphonne IV, it quickly established itself as a power in its own right, expanding to dominate a pocket empire of eight nearby star systems which came to be known as the Gryphonne Octad. Over the centuries that followed, the Mechanicum domain prospered and managed to maintain communication, albeit infrequent and fragmented, with distant Mars. Swearing its domains and arms to the service of the Great Crusade, Gryphonne marched to war at the Emperor's call, and would see its Titan Legion, one of the largest and most ably equipped outside Mars, see immediate action on many battlefronts.
Having extensive experience and proven tactical doctrines in fighting alongside the infantry forces of the Gryphonne Octad, the Legio Gryphonicus quickly gained a reputation for skill in close support of ground troops, and so was much in demand for assignment to the various Expeditionary Fleets. The Legio however was loath to split its forces unduly on deployment, and instead served generally as an independent heavy contingent, assigned to various war zones as strategic needs demanded it. This in turn led to the Legio Gryphonicus amassing battle honours alongside the Dark Angels, Imperial Fists and Death Guard Legiones Astartes at various times, and their inclusion in the order of battle for some of the most famous and vital campaigns of the Great Crusade, such as the Rangdan Genocide and the Ullanor Crusade.
The Mechanicum Reserve of Paramar V and its facilities were later granted as a vassal domain of the distant Forge World of Gryphonne IV by the word of the Emperor as part of the rewards made to the Forge Lords of Gryphonne for their great service and sacrifices during the Crisis of the Hungering Gyre in 891.M30. As well as serving to add greatly to the prestige and power of Gryphonne IV and its Magos -- a factor known to have caused some acrimony with Mars -- Paramar V's defences gained further from this union, becoming a sub-bastion and outer forge of the Legio Gryphonicus, further adding to its importance and breadth of facilities. By the outbreak of the Horus Heresy, Paramar was a strategic locale Warmaster Horus could not readily choose to ignore, but one circumstance and the tide of the Great Crusade had put outside of his sphere of influence.
Hive Fleet LeviathanEdit
Less than five years after the defeat of the Hive Fleet Kraken in the Second Tyrannic War, Lord Inquisitor Kryptman noted the tell-tale signs of yet another Tyranid invasion in 997.M41. He implemented the Kryptman census, burning out dozens of astropaths in the attempt to contact scores of worlds on every fringe of the Imperium. Slowly, the responses - and lack of them - formed a pattern, and the venerable Inquisitor was able to chart the course of the Tyranids' latest Hive Fleet to arrive in the Milky Way Galaxy. Codenamed "Leviathan", this time the Tyranids were approaching from below the galactic plane, attacking from two points spaced wide apart in the shape of a closing pair of jaws, cutting off large portions of the galaxy from Warp travel or astropathic communication. At a great cost in human life, a combined force of Planetary Defence Force troops, two Regiments of the Imperial Guard, the Ultramarines and Mortifactors Chapters of Astartes, and a Deathwatch Kill-team under the command of Inquisitor Kryptman crushed the left "half" of the Leviathan on the world of Tarsis Ultra, destroying the Tyranids nearest to Terra, and reestablishing astropathic contact with the worlds between Leviathan's jaws. The Imperium had won its first victory.
Yet Leviathan continued to carve its bloody path through the Imperium. Perhaps Leviathan's main gain was the vital Forge World of Gryphonne IV, home of the Legio Gryphonicus Titan Legion. Kryptman knew he had to slow down the Hive Fleet's advance to buy time for the Imperial Navy's Battlefleets Solar and Tempestus to muster. With grim finality, he ordered a cordon to be established. Every world within was to be evacuated and undergo immediate Exterminatus wherever possible, thus causing the Tyranids to expend their forces for little gain, the Exterminatus denying them valuable biomass to replenish themselves. With one stark, callous decision, the Inquisitor had inflicted the Imperium's worst act of genocide upon on its own since the Horus Heresy. Kryptman was denounced as a radical and a traitor; when migrating Orks claimed a score of former human worlds, he was stripped of his title and cast from the Inquisition by his brethren.
The Adeptus Mechanicus refused to abandon this important Forge World to Exterminatus. Isolated and alone, and left for dead in an abandoned star system, the Legio prepared for war. Before the arrival of the Hive Fleet, Gryphonne IV boasted some of the finest defences of any Imperial world within the southern reaches of the galaxy. Gryphonne IV's War Griffons Titan Legion was feared for its world-breaking firepower and its Skitarii legions, whom were envied across the Adeptus Mechanicus for their discipline and precision. Yet, it was not enough to halt the Tyranid onslaught. The Skitarii were annihilated and devoured by waves of inexhaustible Hormagaunts and their Titan Legions torn asunder by Tyrannofexes and Tyranid Bio-Titans. Gryphonne IV was ever after a Dead World -- a grim testament to the folly of hubris and pride. The Legio Gryphonicus was presumed to be destroyed in the conflict, but later appeared during the 13th Black Crusade, to help augment Imperial forces by deploying the entire Legion in defence of the Fortress World of Cadia.
- Codex: Eye of Terror (3rd Edition), pg. 16
- Codex: Tyranids (5th Edition), pg. 28
- Imperial Armour Volume One - Imperial Guard and Imperial Navy, pp. 31-46, 53-60
- The Horus Heresy - Book Three: Extermination, pp. 19, 160-161