Event · M41
Kryptman’s War
Kryptman’s War is the Imperial campaign against Tyranid hive fleets in the Ultima Segmentum, associated with the Ordo Xenos Inquisitor Kryptman. It is recorded within the 41st Millennium, in the era of the Tyrannic Wars, and is anchored on Macragge, the Ultramarines’ capital world and the site of the earliest decisive Imperial victory over a hive fleet. The name is applied to the Inquisition-led effort to understand and contain the Tyranid threat, and accounts differ on its precise start and end dates and on how far it is treated as a distinct war rather than a phase of the wider Tyrannic Wars. The cause was the arrival of the Tyranids from beyond the galactic rim, beginning with Hive Fleet Behemoth, whose advance on Ultramar ended at Macragge under the Ultramarines Chapter Master Marneus Calgar. That defeat left the Imperium aware that later fleets would follow, and it raised the Ordo Xenos’ standing in Tyranid policy. Inquisitor Kryptman is recorded as an advocate of drastic measures, including Exterminatus of threatened worlds to deny the swarm biomass, and later tradition ties his name to the stratagems known as the Kryptman Gambit and the Kryptman Cull. The principal participants were the Ordo Xenos, the Ultramarines and their Ultramar successors, and Imperial Navy and Planetary Defence Force units drawn into the fleets’ path. The aftermath is one of contested doctrine. The Imperium’s policy of sacrificing worlds for time remains disputed within the Inquisition, and the Tyranid threat to the eastern and southern reaches has persisted through later hive fleets, among them Kraken and Leviathan. On the Orrery map and timeline, the war links Macragge and Ultramar to the Tyrannic Wars and to the Ordo Xenos, and it is best read alongside Hive Fleet Behemoth and Marneus Calgar, which are its nearest neighbours in the graph.
See where Kryptman’s War occurred on the galactic map in the 41st Millennium.