|This article is about the the Hive Fleet. For other uses of Kraken, see Kraken (disambiguation).|
The invasion began 250 years after the last Tyrannic War and the destruction of the hive fleet Behemoth. An armed presence had been maintained in the galactic southeast, which members of Earth's Administratum began to question the need for, arguing that Behemoth had been the sum total of the Tyranid race. When worlds along the eastern fringe began to erupt in rebellion, terrorism, riots and sabotage, the same adepts claimed the people were dissatisfied with living amid an armed camp. Among the first worlds known to be consumed by Kraken were Sotha, Miral, Graia and Radnar.
The Inquisition became suspicious of the adepts' dissent and their downplaying of the situation, and began an investigation, which established that all of the dissenting adepts had either come from the southeastern region or had travelled there at some time. This was the only link between the members that could be found, and some had never even met each other. Inquisitors were also deployed from Talasa Prime to investigate the planets of the Ultima Segmentum who were displaying their anger. Purges were made within the Imperium, especially on Terra, focused on suspected traitors, who had had contact with the Eastern Fringe. Tens of thousands of suspected traitors were sent to prison colonies.[Needs Citation]
Ichar IV Campaign
The Battle for Iyanden
In 992.M41  the Eldar Craftworld of Iyanden suffered its greatest tragedy at the claws of Hive Fleet Kraken. Around the same time that one tendril of the Hive Fleet was assaulting Ichar IV, another was approaching the Craftworld, one of the largest and most populous of the Eldar. The attack was repelled thanks to the efforts of Prince Yriel, but only at severe cost.[5c]
Fall of Sotha
With the defeats at Ichar IV and Iyanden, Hive Fleet Kraken splintered and its remnants moved towards the Galactic Core.[5a] However this was not the end of the Tyranid menace, for they would be followed by the even larger Hive Fleet Leviathan. In addition, Kraken's splinter fleets and remnants continued to ravage parts of the Galaxy.
- The Battle of Hollonan — In response for a request for assistance in putting down a seemingly minor rebellion, Chief Librarian Mephiston of the Blood Angels would lead a strike force to the Imperial Hive World of Hollonan. However what was first thought to be a minor rebellion is soon revealed to be a massive infestation by Tyranid Genestealers of a splinter fleet of Hive Fleet Kraken. Though they manage to purge the alien infestation, the Blood Angels are too late and the invasion of Hollonan by Tyranid Bio-ships is already underway. Realizing the gravity of the situation, Mephiston sends requests for aid to the Angels Vermillion Space Marine Chapter.[4g] In the ensuing battle waves of Tyranids manage to overrun both the planetary defense batteries and fusion reactors. Only where Mephiston fights do the forces of humanity hold in a vicious two week battle. Managing to personally slay the Hive Tyrant, Mephiston himself is struck down by a Trygon in the process. As the battle seems increasingly desperate, fresh companies of Blood Angels and Angels Vermillion emerge from the sky in Drop Pods and Stormraven Gunships. The forces of humanity are further aided by the Eldar of Ulthwé Craftworld under Farseer Eldrad Ulthran, which has chosen to temporarily ally with the Imperium for their own mysterious reasons. Caught between the 3 armies, the Tyranids are crushed. Eldrad remains just long enough to see Mephiston recovered by the rubble before the Space Marines and Eldar go their separate ways.
- Damocles Gulf Campaign — An outer wing of Hive Fleet Kraken entered the Damocles Gulf in 991.M41 and encountered a tau exploration vessel in the Coreward Marches, which was able to get off a courier drone before self-destructing. In response to the invasion, in 992 the Tau Empire aborted its invasion of the Imperial planet Quadravidia and offered to ally with humanity against the tyranids. Lord General Zyvan accepted the alliance and provided astropaths to serve aboard tau ships as liaisons. The main force of Battlefleet Damocles planned to intercept the splinter fleet at Quadravidia, but an Imperial task force consisting of approximately 100 warships under Admiral Boume and Imperial Guard regiments from the Death Korps of Krieg was stationed at the strategic Forge World Fecundia, joining local Skitarii and a small garrison of Adeptus Astartes of the Reclaimers chapter. Also present was the famed Commissar Ciaphas Cain. In the ensuing battle the Imperial forces realized that the Kraken hive mind wished to destroy a fragment of a bioship that had been recovered from Nusquam Fundimentibus in 941 and transported to Fecundia for study. Realizing from their behavior that the two competing hive minds were partially neutralizing each other, the Imperial forces hit upon using an astropath, Clementine Drey, as an amplifier to broadcast the fragment's signal into the attacking fleet to disrupt its command-and-control. At the cost of her life, Drey helped the Imperial Navy to gain the upper hand, forcing the tyranids into full retreat. Following the victory, the Imperial Guard established a permanent garrison on Fecundia, which was officially declared cleansed by 058.M42.
- Mortrex Overrun — The Imperial world of Mortrex is overwhelmed by unrelenting tides of Ripper Swarms. The dread beast known as the Parasite of Mortrex spawns thousands of these mindless feeder-beasts from the still-living bodies of its victims.[13a]
- Mystery of Adri's Hope — A refugee ship from Devlan arrives in orbit around Adri’s Hope, ominously silent. Those investigating the ship find it to be an abattoir, all aboard mercilessly butchered. Though a breach of quarantine is suspected to have allowed a Tyranid organism to get aboard, nothing is found. Three weeks later, all contact is lost with Adri’s Hope.[13a]
- Goethe's Last Stand — Princeps Goethe of the Imperator Titan Mettalum Olympus single-handedly manages to hold back a tendril of Hive Fleet Kraken on the ash-choked plains of Horst Prime. The mighty war engine is finally destroyed when a brood of Hierophant bio-titans pounce on the noble machine like a pack of wild dogs. In the frenzied attack, Mettalum Olympus’ plasma reactor is breached and the resultant explosion vaporises everything for a mile around, leaving behind a crater that is still visible from orbit – a testament to the sacrifice needed to fight the Tyranids.[13a]
- The Ork Freebooter blunted a tendril of Kraken while aiding Warboss Garaghak by launching a daring raid on the Norn Queen at its heart.
- The War for the Aberrus System
As Hive Fleet Leviathan emerged, a remnant of Kraken that had been thought lost in a Warp Storm returned, apparently attempting to fuse with Leviathan. Had they done so, the bio-information gathered by Kraken could have been used with Leviathan's resources to create a new mighty strain of Tyranid. Fortunately, this remnant of Kraken was defeated at the Battle of Duriel.
The creatures of Hive Fleet Kraken have a colouring pattern of bone skin with red carapaces and usually bone or black weapon symbiotes.
Known Splinter Fleets of Hive Fleet Kraken include:
- Splinter Fleet Formund Ultra[19a]
- Splinter Fleet Ichar Magna[19d]
- Splinter Fleet Miral Rex[19c]
- Splinter Fleet Sotha Secundus[19b]
- 1: Codex: Tyranids (2nd Edition), pgs. 12-14
- 2: Warhammer 40,000 3rd Edition Rulebook,[Needs Citation]
- 3: Codex: Tyranids (3rd Edition),[Needs Citation]
- 4: Codex: Tyranids (4th Edition) [Needs Citation]
- 5: Codex: Tyranids (5th Edition)
- 6: Codex: Eldar (4th Edition), pgs. 52–53
- 7: Orphans of the Kraken (Short Story)
- 8: Codex: Blood Angels (5th Edition), pg. 17
- 9: Warhammer 40,000 6th Edition Rulebook, pg. 175
- 9: Codex: Tyranids (4th Edition), pg. 59
- 10: Iyanden: A Codex: Eldar Supplement (E-Book) pgs. 45–47
- 11: Codex: Tyranids (6th Edition) (E-Book Edition) — Ichar IV
- 12: The Greater Good (Novel),[Needs Citation]
- 13: Codex: Tyranids (8th Edition)
- 14: Codex: Tyranids (4th Edition), pg. 14
- 15: White Dwarf 218 (UK), pg. 80
- 16: Orphans of the Kraken (Short Story)
- 17: Belisarius Cawl: The Great Work (Novel), Chapter 24
- 18: Codex: Orks (8th Edition), pg. 67
- 19: Warhammer: Visions 1
- 20: Codex: Space Marines (9th Edition) pg.24-25