Hive Fleet Kraken

From Warhammer 40k

The second wave of Tyranids to fight against the Imperium was known as "Hive Fleet Kraken". Its arrival was heralded by a score of genestealer rebellions and insurrections on the Eastern Fringe. Instead of throwing one mass of troops against the human armies, this swarm split into countless smaller fleets, each one enveloping whole systems before reinforcements could arrive. Although this made each individual assault weaker and made some warp travel and communication possible, Kraken was attacking across a far vaster front than Behemoth. Two Space Marine Chapters based on the Eastern Fringe - the Lamenters and the Scythes of the Emperor - were all but annihilated. A vast portion of Kraken's strength attacked the Eldar Craftworld of Iyanden. Although eventually defeated, the attack killed four-fifths of the Craftworld's population; a terrible blow to the dwindling Eldar race.

As the fleet faced more severe resistance, smaller sub-fleets would combine to overcome it, narrowing the range of the Hive Fleet's attacks as it pushed further into Imperial Space. After the Ultramarines crushed a genestealer insurrection on Ichar IV, the Imperium's psykers were able to determine where the remainder of Kraken's strength was converging upon. Troops were rushed to Ichar IV ahead of the Tyranids. Marneus Calgar was elected Supreme Commander among the coalition of Imperial Guard, Space Marines and Imperial Agents, and once again led the Imperium to victory. According to Lieutenant Kage of the Last Chancers penal regiment, the Imperial Guard "Lost over a billion men at Ichar IV". Kraken was not fully destroyed, and after Ichar IV, split into several splinter fleets. Although tiny by comparison, they pose a threat to isolated or poorly defended worlds, and have slipped far beyond the cordon established to combat Kraken.