|Events by Year (Imperial calendar)|
- (138997.M41) The Tyranid Hive Fleet Leviathan causes huge amounts of damage across Segmentums Temcestus, Ultima and Solar.
- (221997.M41) Piscina IV is invaded by Orks under the joint leadership of Ghazghkull Thraka and Nazdreg. Although taken by surprise by Orkish teleportation, a group of Dark Angels led by Belial defend the planet until reinforcements arrive and end the threat.
- (509997.M41) A number of Ultramarines and Mortificators battle against a wave of Hive Fleet Leviathan on Tarsis Ultra. The Tyranids on the planet are defeated with a biological plague, but the rest of Hive Flee Leviathan continues to ravage elsewhere.
- (622997.M41) Dark Eldar raiders slaughter refugees from Golgothan on the moon of Jagdor.
- (977997.M41) Tau forces begin a third phase of expansion. Several imperial worlds are captired on the Eastern Fringe.
- (601997.M41) Commissar Yarrick and Warlord Ghazghkull battle face to face on Golgotha. Yarrick is captured but ultimately released as Ghazghkull intended to invade Armageddon and wanted a good fight.
- (???997.M41) Daemon Prince Khalathrac is decapitated by the tyranid Swarmlord, during an assault on the Chaos Citadel of Terrofane.