• 123.M40 The Threefold Curse - Two heavily defended Battlefleet Calixis watch-stations and a sizable capital ship taskforce, lead by the Grand Cruiser Fire of Heaven, are destroyed by unknown assailants in the outer reaches of the Hazeroth Abyss, forcing an Imperial retrenchment, effectively shrinking the border of the sector and ending further military expansion in the region. The only clue to the cause is found carved on a bulkhead in the hulk of the watch-station Sentry-17, which reads, “The worms that walk have come for us all”.
• 433.M40 Imperial Governor of planet Krieg declares his world's independence and renounces the Emperor. Colonel Jurten of the Imperial Guard regiment the Krieg 33rd unleashes a campaign of atomic cleansing that lasts 5 years to put down the rebellion, turning the world of Krieg into a radioactive wasteland. From then on, the Death Korps of Krieg's forces embark on a quest of absolution for this terrible deed.
• 552-570.M40 The White Sorrows - Dark Eldar corsairs of the Kabal of the White Sorrow plague the area of space known as the Periphery with a devastating series of raids. The corsairs are shattered and their threat ended at last when confronted and brought to battle by a force consisting of Battlefleet Calixis, Explorator and Rogue Trader forces (aided it is rumoured by unknown xenos forces) under the overall command of the Rogue Trader Kobras Aquairre. The battle turns when Aquairre’s flagship, The Son of Seth, successfully rams and boards the corsair flagship Altar of Torment, Kobras himself slaying the enemy’s Butcher Archon in single combat.
• 561.M40 Nexxas Exculpation. The Emperor's Children Chaos Space Marines face the forces of the Imperial Guard on the world of Nexxas.
• 666.M40 An Imperial patrol force first engages Necron warships in the Yuctan System. Only a single Cobra-class destroyer escapes; when an Imperial fleet returns to the system, all the colonists are missing.
• 675.M40 Hive World of Vidium lost to the Dark Eldar.
• 709.M40 Tanis Incident - The thriving Hive World of Tanis and its surrounding star system, which had been an outer bulwark of the Calixis Sector’s power in the Hazeroth sub-sector, is visited by an unexplained stellar phenomena in the shape of a baleful black “Tyrant Star” that presages destruction, madness and death. Within a period of weeks, the Tanis System is ravaged, resulting in over two billion dead or missing. Survivors are only found on the Agri-moon of St. Astrid’s Fall, which itself is badly ravaged. The “Tanis Incident” is covered up with full Inquisitorial authority and declared a forbidden subject on pain of death. Civil data is adjusted accordingly so that Tanis never existed in the public records of the sector. This event, taken with a long and erratic slew of other dark mysteries and a rising weight of deadly prophesy, leads to the formation of the current incarnation of the Inquisition's Tyrantine Cabal to investigate the matter and take whatever action is necessary to combat what is now classified as the phenomena of the Hereticus Tenebrae.
• 738-741.M40 The War of Brass - The Hive Worlds of the Gelmiro Cluster fall into sedition against the Imperium, following the charismatic leadership of a figure calling himself the “Emperor of Brass”, debasing themselves into the worship of the Ruinous Powers. Heavily militarised, the Renegades quickly sponsor and arm rebel groups on nearby worlds and when counter-attacked, reveal the hand of dark forces from the Eye of Terror in their ranks. The so-called “War of Brass” that followed was comparably brief but bloody, involving forces drawn from across the sector, and the involvement of the Adeptus Astartes and the Titans of Legio Venator, it rendered the once thriving worlds of Gelmiro blasted, rubble strewn rocks. Classified as War Worlds and the haunt of murderous scav-mutants, Renegades and wreakers ever since, the Gelmiro System is still a shunned no-man’s land to this day.
• 924.M40 Vindicare Assassin destroys an Ork Gargant and terminates the Greenskin Warlord Urglak the Unstoppable on the world of Roxanzand.
• 941.M40 Ork Warboss Ghazghkull Mag Uruk Thraka and the five tribes of Orks he leads invade the Hive world of Armageddon in the Segmentum Solar and unleash the Second War for Armageddon.
• 989.M40 Eldar Craftworld Yme-Loc first detected in the West Quadrant of Segmentum Obscurus.

This article is a stub. You can help the Warhammer 40k Wiki by fixing it.

M39	Timeline	M41