|143.M41

|The [[Jorun Retaliation]]. The [[Howling Griffons]], [[Ultramarines]] and [[Sons of Orar]] Chapters defeat the [[Cabal of the Crimson Libation]] and their ex-[[Imperial Guard]] slaves. [[Chaplain]] [[Armand Titus]] of the Howling Griffons is interred within a [[Dreadnought]] sarcophagus after succumbing to the Xenos poisons.

|-

|154.M41

|220.M41

|[[Explorator Fleet Hydrax-Lamda-15]] discovers an Ork [[Terror Ship]] adrift in space. The ship is devoid of life, but contains the corpses of hundreds of Orks. A standard bearing the words '[[Carcharodon Astra]]' is found atop a mound of bodies several metres high.

|-

|241.M41

|rowspan=2|666.M41

|The [[Battle for Grand Al'gul]].

|-

|The [[Yuctan Incident]] - The entire population of [[Yuctan]], including a [[Imperial Navy|Naval]] depot housing squadron ''[[Squadron Farsight|Farsight]]'', vanishes following an encounter with [[Necron]] raiders. A single [[Cobra destroyer]] survives to tell the tale.

|698-705.M41

|The [[Corinthian Crusade]]. [[Chapter Master]] [[Marneus Calgar]] of the [[Ultramarines]] leads the crusade, which consists of Ultramarines, [[Angels of Absolution]], [[Lamenters]], [[Silver Skulls]], [[Scythes of the Emperor]], [[Marines Errant]] and over fifty [[Imperial Guard]] regiments. [[Waaagh!]] [[Skargor]] is crushed and the threat from the [[Ork]]s of [[Charadon]] is diminished for over thirty years.

|}

|738.M41

|[[26th founding|Latest Founding]] (26th).

|-

|739.M41

|[[Wolf Lord]] [[Finn Goresson]] boards the gargantuan [[Ork]] warship ''Starkrusha'', with a small force of [[Space Wolves]]. Six months later, he emerges from the ship with [[Warboss]] [[Godstompa]]'s head hanging from his belt.

|-

|740.M41

|The [[Exorcists]] Chapter save the planet of [[Stonekraal]] from a large [[Genestealer]] infestation.

|-

|740-743.M41

|rowspan=3|741.M41

|[[Inquisitor]] Bastalek Grim attends the Great Feast of [[Wolf Lord]] [[Gerrod Redbeard]], committing the sagas recounted there to his eidetic implants. From these he creates Imperial records later titled "The War of the Giants."

|-

|Following a costly victory over [[Imperium|Imperial]] [[Titan Legion]]s on Malaxis, the [[Autarch]]s of the five largest [[eldar]] [[craftworlds]] convene. They decide that the lesser races must be shown their place; their message spreads across the craftworlds, resulting in the largest recruitment of eldar taking the Path of the Warrior in millennia. Many civilian paths are abandoned as a result.

|754-756.M41

|The [[Salamanders]] Chapter purge the [[Moons of Ymgarl]] of [[Genestealers]]. [[Space Marine Captain|Captain]] [[Sokhar Bray'arth]] of the 4th Company is interred in the [[Iron Dragon]] [[Dreadnought]] chassis after suffering mortal wounds.

|-

|754.M41

|755.M41

|The [[Sabbat Worlds Crusade]], the largest Imperial offensive since the [[Macharian Crusade]], begins.

|-

|757.M41

|772.M41

|[[He'stan Vulkan]], [[Forgefather]] of the [[Salamanders]], recovers the [[Gauntlet of the Forge]] after defeating the [[Eldar]] pirate lord [[Iath Bloodweaver]].

|-

|773.M41

|775-777.M41

|[[Sulsalid Campaign]], [[Fourth Quadrant rebellion]].

|-

|777.M41

|780.M41

|[[Lycanthos Drift Campaign]], [[Fourth Quadrant rebellion]].

|-

|781.M41

|[[Wolf Lord]] [[Osric Three-Fists]]'s fleet is ambushed in the [[Maelstrom]] by a larger [[Chaos]] fleet. When his flagship is crippled, Osric leads the remains of his [[Great Company]] in a boarding action of the Chaos flagship ''Storm of Hate''. Only thirty [[Space Wolves]] board the ship, but manage to capture the ship and turn its firepower on the rest of the Chaos fleet.

|-

|783.M41

|[[Battle of Maedrax]]. [[Eldrad Ulthran]] of [[Ulthwé]] foresees an Imperial explorer force would awaken the [[Necron]] tomb world. The [[Eldar]] destroy the explorer fleet and then the Necron complex. When leaving Maedrax, they have to fight their way through a relief force of [[Blood Angels]] [[Space Marines]]. Unfortunately, the Necron [[dynasty]] is much larger than Eldrad believed; tomb worlds across the system awaken.

|-

|785.M41

|-

|The [[Astronomican]] flickers, resulting in thousands of ships being lost in the [[Warp]].

|-

|[[Hive Fleet]] [[Naga]] enters the galaxy from the [[Eastern Fringe]].

|-

|803.M41

|rowspan=2|812.M41

|Fleets from the [[Malan'tai]], [[Iyanden]], and [[Idharae]] [[Craftworld]]s eliminate [[Hive Fleet]] [[Naga]], but a single [[Doom of Malan'tai|bioform]] infiltrates and consumes Malan'tai.

|-

|The [[Purging of Contqual]]. The [[Iron Hands]] drive the forces of [[Chaos]] from a dozen planets on the [[Contqual]] subsector.

|-

|812-813.M41

|The [[Luxor Uprising]]. The [[Novamarines]] crush an [[Alpha Legion]]-sponsored insurrection on [[Luxor (Helioret Sector)|Luxor]].

|-

|199812.M41

|rowspan=2|815.M41

|Contact is lost with Explorator Fleet 913. Three companies of the [[Ultramarines]] are sent to investigate, but find only empty vessels drifting in space.

|-

|[[Dal'yth]] [[sept]] receives unexpected aid from Commander [[O'Shovah|Farsight]] to repel an invasion by the [[Ork]] [[warboss]] [[Grog]].

|818.M41

|[[Throth Half-Head]] of the [[Space Wolves]] defeats the giant [[Ur-Bolg]] wreaking havoc on [[Fenris]].

|-

|649818.M41

|rowspan=2|819.M41

|A perceived insult provokes fighting between the [[Mortifactors]] and the [[Crimson Fists]]. Only an intercession by [[Ultramarines]] [[Chapter Master]] [[Marneus Calgar]] prevents open war, and the incident is kept secret from the [[Adeptus Terra]].

|-

|An outbreak of contagious madness and despair affects Ilsig Hive on Chemarium II, causing thousands to kill themselves. Civil order collapses. Ranker Nonesuch, the self-titled "Beggar King," arises to lead his followers to overthrow the planetary government and spread his malevolence to the rest of the system. An exclusion zone is established around the system.

|-

|[[Wolf Lord]] [[Erik Morkai]] ambushes the pirates of the [[Kabal of the Shattered Hand]] over the Leutin Necropolis.

|-

|101822.M41

|833.M41

|The [[Vinculus Crusade]] is fought by [[Black Templars]] and [[Sisters of Battle]] of the [[Order of the Bloody Rose]] under the command of [[Marshal]] [[Ludoldus]] and [[Canoness]] [[Jasmine]] against an assassin-cult on [[Peleregon IV]]. The [[Daemon]]-possessed [[Inquisitor]] [[Vinculus]] is slain.

|-

|835.M41

|837.M41

|[[Space Wolves]] and [[Flesh Tearers]] fight, brother against brother, in a dark moment for both [[Chapters]] at the battle of [[Honour's End]].

|-

|841.M41

|Ninety-four years after the [[Battle for Macragge]], the [[Ultramarines]] [[First Company]]'s operational strength exceeds fifty percent for the first time.

|-

|rowspan=2|845.M41

|[[Dark Eldar]] pirates capture [[Warmaster]] [[Ingenus]], commander of the [[Dimmamak War]], escalating the situation. In response, all high ranking [[Imperial Guard]] officers are assigned bodyguards and another forty thousand regiments are raised.

|-

|The [[Blood Swords]] [[chapter]] purges the [[Inando]] system. More than one hundred billion Imperial citizens are slain in the resulting [[Exterminatus]] actions.

|-

|rowspan=3|849.M41

|[[Cato Sicarius]], [[Space Marine Captain|Captain]] of the [[Ultramarines]]' Second Company, is appointed [[High Suzerain of Ultramar]].

|-

|All contact is lost with [[Birmingham]], the Black Planet. Subsequent investigations confirm a [[Dark Eldar]] massacre.

|-

|The 813th [[Feast of Blades]]. [[Hervald Strom]] of the [[Iron Knights]] is victorious yet again, despite suffering heavy wounds in the [[Vinculus Crusade]]. It is the first time in the history of the event that a single Chapter, let alone a single Champion, has won two successive victories.

|-

|850-901.M41

|855.M41

|The [[Assault on Black Reach]]. The [[Ultramarines]] Second Company under Captain [[Cato Sicarius]] defeats [[Waaagh!]] [[Zanzag]] on [[Black Reach]].

|-

|rowspan=2|857.M41

|863.M41

|The [[Saint Cyllia Massacre]]: The [[Adamant Fury]] [[Titan Legion]] falls to Chaos and massacre the [[Saint Cyllia]] [[PDF]] before escaping¹. Leading the Cadian 423rd, Knight Commander [[Pask]] engages rearguard elements of the traitor Titan Legio.²

|-

|865.M41

|The Purging of [[Modanna]], [[Kor'sarro Khan]], [[Master of the Hunt]] of the [[White Scars]], drives the [[Daemon Prince]] [[Kernax Voldorius]] from his most important fortress.

|-

|867.M41

|rowspan=2|883.M41

|The largest armoured assault since the [[Battle of Tallarn]], spearheaded by the [[Cadian 423rd]], attacks and nearly annihilates a renegade [[Titan Legion]] in a battle on the [[Planus Steppes]]. Imperial forces are to endure the loss of over eight thousand tank companies and thirty five super-heavy detachments.

|-

|[[Dark Eldar]] warriors of the [[Kabal of the Black Heart]] raid Imperial Munitions Relay Base 359, causing the western Imperial flank to collapse during the Irgax Offensive and threatening the stability of the Imperial presence on Kyobin and the entire subsector.

|886.M41

|A deputation from the [[Ecclesiarchy]] visits the [[Space Wolves]]' homeworld of [[Fenris]], planning to investigate rumours of pagan worship. The Wolves open fire on the fleet, provoking a three-week war between the Wolves and three orders of the [[Adepta Sororitas]], which ends when the Ecclesiarchy decides to retreat.

|-

|rowspan=2|888.M41

|The [[Battle for Orar's Sepulchre]]. The entire [[Ultramarines]] [[chapter]] goes to war for the first time since the [[Battle for Macragge]] to defend [[Orar's Sepulchre]] on planet [[Commrath]] from [[Eldar]] forces from [[Craftworld]]s [[Alaitoc]] and [[Iyanden]]. In the final battle, [[Marneus Calgar]] defeats the Alaitoc [[Avatar]] in single combat.

|-

|The Crusade of Wrath: [[Black Templars]] defeat the [[Word Bearers]] and reclaim many worlds near the [[Maelstrom]].

|897-903.M41

|[[Hive Fleet]] [[Gorgon]] eats through the [[Tau Empire]] until a combined force of Tau and [[Imperium of Man]] fleets stops it at [[Kel'shan]].

|-

|899.M41

|The [[Battle of Carrion Deep]]. One of the first confirmed and detailed conflicts between the Imperium and the rising Necron threat.

|-

|}

|901-912.M41

|[[Lufgt Huron]], [[Chapter Master]] of the [[Astral Claws]], revolts. An Imperial investigation fleet is destroyed in orbit of [[Badab]], killing 23,000 agents of the Imperium. Huron declares himself Tyrant of Badab and secedes from the Imperium. The [[Badab War]] follows.

|-

|902.M41

|The [[Thirteenth Castigation of Golgotha]] is carried out by the [[Fire Hawks]] Chapter.

|-

|903.M41

|-

|[[Hive Fleet]] [[Gorgon]] is destroyed by the combined forces of the [[Tau]] and the [[Imperial Guard]].

|-

|rowspan=2|904.M41

|[[Badab War]]: the [[Fire Hawks]] retaliate when their supply ship is captured by the Mantis Warriors.

|-

|A [[Chaos]] incursion on [[Paraghast]] turns Patrihive into a nightmarish twisted prison. Billions of souls fight [[daemon]]s of [[Nurgle]] and [[Slaanesh]] as their home hive turns against them.

|rowspan=2|905.M41

|[[Badab War]]: the [[Marines Errant]] are recalled from [[Eastern Fringe]] but find themselves protecting convoys more than actively attacking the rebels.

|-

|[[Siege of Castellax]]: The [[Iron Warriors]] [[Fortress World]] of [[Castellax]] is invaded and overrun by [[Waaagh!]] [[Biglug]]

|-

|rowspan=2|906.M41

|-

|[[Badab War]]: [[The Betrayal at Grief]] - Lord High Commander [[Verant Ortys]] of the [[Red Scorpions]] is killed under an attack by unknown forces during a meet between the Loyalist and Secessionist forces. The Chapter Master of the [[Mantis Warriors]] [[Sartaq]] is also killed. [[Lufgt Huron]] is later blamed for this incident.

|-

|907.M41 (913?)

|[[Badab War]]: Several [[chapter]]s are redeployed in response to [[Ork]] expansions in the [[Ultima Segmentum]] and the [[Imperial Navy]] assumes their responsibilities. Badab is blockaded, while more chapters are brought in to investigate the [[Executioners]] and [[Mantis Warriors]]' worlds.

|-

|908.M41

|[[Badab War]]: The bulk of the Lamenters are caught in an ambush and surrender to loyalist forces.

|-

|908-912.M41

|[[Badab War]]: A series of sieges see the fortresses of Huron crumble to the loyalists. Badab is eventually surrounded and cut off.

|-

|rowspan=3|912.M41

|-

|The [[Death Korps of Krieg]] are sent to the world of [[Derondii]] in punishement for withheld tithes. The Death Korps spend the next ten years bombarding the world's cities to rubble, five years after recieving an unconditional surrender and two years after the last sign of life is spotted.

|-

|912.M41-Present

|921.M41

|[[Marneus Calgar]], [[Chapter Master]] of the [[Ultramarines]], is ambushed by the [[Night Lords]] while en route to the [[Darkhold]] battlezone, and his ship crash-lands on the feudal world of [[Barathred]]. Several hundred [[Chaos Space Marines]] of the Night Lords make planetfall, but under Calgar's leadership, the planet's feudal population rises up and defeats them.

|-

|922.M41

|rowspan=2|925.M41

|Contact lost with eighteen planets in the Vidar sector, including the forge world Lentrel Prime.

|-

|[[Waaagh!]] [[Grax]] invades the [[Ryza]] system. Regiments are raised from planets within ten light years, including the worlds of [[Barac]], [[Ulani]], [[Dulma'lin]] and [[Catachan]]. To meet demand, four-fifths of Dulma'lin's populace is drafted. The Orks would eventually be broken decades later at the [[Battle of Desolation Valley]] by Commander [[Mordrid van Hordric]].

|-

|rowspan=3|926.M41

|930.M41

|The Orks under [[Krakskull]] are destroyed in a trap in a ravine on [[Arandra V]] by the [[Catachan Jungle Fighters#Notable Regiments|Catachan XXIV 'Waiting Death']].

|-

|rowspan=2|931.M41

|-

|The [[Hammeront IV]] are charged with desertion by the Departmento Munitorum and their commander, Lord General [[Lourgant]], is posthumously sentenced to death.

|-

|932.M41

|[[Magus]] [[Stannum Vir]] discovers a priceless [[STC]] relic on the [[Agri world]] of [[Jollov]]. Combined elements from [[Catachan Jungle Fighters|Catachan]], [[Mordian Iron Guard|Mordian]], [[Kanak]], [[Molov]], and [[Agathon]] regiments sacrifice themselves defending the spaceport from [[Hive Fleet Moloch]], buying Vir enough time to recover the artifact and escape.

|-

|rowspan=2|933.M41

|rowspan=2|935.M41

|[[M'kar]] returns from the [[Warp]] and seizes control of the [[Ramilies|star fort]] ''[[Indomitable]]'' with a horde of [[Daemon]]s, in the outer orbit of [[Calth]]. [[Marneus Calgar]] leads [[Terminator]]s from the [[Ultramarines]] [[First Company]] aboard the fort and defeats the Daemon Prince. M'kar is officially listed as destroyed, but Calgar later confesses that he was forced to imprison the Daemon within the star fort's warp core and set it adrift. Half of the Ultramarines' 5th Company is stationed aboard the fort to guard the daemon's prison.

|-

|An Imperial Guard offensive on [[Bren's World]] is stalled when it fails to overcome the defences of [[Haven's Spire]]. Elite [[Storm Trooper]] units break the deadlock by destroying several [[void-shield]] generators.

|936.M41

|[[Hive World]] [[Derondii]] withholds its annual [[tithe]]s. The [[Death Korps of Krieg]] are deployed as an honour guard for the [[Departmento Munitorum]] investigation team. After locals lynch the team, the Death Korps levels the primary [[hive city]] with a ten-year artillery barrage.

|-

|rowspan=4|937.M41

|rowspan=2|939.M41

|While serving with the 70th [[Luther McIntyre]] [[regiment]] on [[V'run]], responding to [[Ork]] attacks occurring throughout the [[Segmentum Solar]], [[Commissar Yarrick]] learns the Ork language from a captured greenskin.

|-

|A [[Chaos Space Marine]] ambush kills [[Dark Angels]] [[Supreme Grand Master]] [[Naberius]]. [[Azrael]] leads the [[Deathwing]] to recover his body and is named his successor.

|-

|The conquest of [[Atria IV]] grinds to a halt outside the Palace of Hate, impregnable to the Imperial forces.

|-

|941.M41

|rowspan=2|949.M41

|The 814th [[Feast of Blades]] is held. Only eight of the twelve competing [[Space Marine]] [[chapter]]s are able to attend. The championship is tied between the [[Imperial Fists]] and the [[Crimson Fists]].

|-

|[[Dark Angels]] [[Librarian]] [[Ezekiel]] kills [[Ork]] Warlord Groblinik in the Battle of the Sularian Gate, ending his [[Waaagh!]]

|955.M41

|The [[Imperial Fist]] siege of the mega-fortress [[Fort Mork]] is nearly overwhelmed when thousands of [[Orks]] pour from the gates in a counter-attack.

|-

|956.M41

|-

|During an attack on the Imperial city of Chalior, the [[Eldar]] [[Phantom Titan]] ''Heart of Eldanesh'' is destroyed by a [[Vortex Missile]] launched from the Grand Redoubt protecting the city.

|-

|967.M41

|974.M41

|The [[Damnos Incident]]. The [[Ultramarines]] Second Company, led by Captain [[Cato Sicarius]], rescues survivors from the doomed world of [[Damnos]] as the [[Necrons]] on the planet awaken.

|-

|rowspan=4|975.M41

|-

|The Liberation of [[Amadis]]. Regan Antigone, the sole survivor of the Procell 1st Irregulars, is hailed as the man who rallied and organized the defenses that held off the final wave of the rebel attack before the [[Dark Angels]] arrive. He swears to never reveal the role or even the existence of the [[Cypher|robed figure]] who truly won the battle.

|-

|978.M41

|rowspan=2|980.M41

|[[Chaos Lord]] [[Brule]] and his [[Chaos Space Marines]] are destroyed on [[Treconodal]] by a combined force of the [[Cadian 8th]] and the [[Terrax Guard]].

|-

|The [[Promethean War]]. The [[Salamanders]] fight an urban war against the [[Black Legion]] on [[Heletine]]. The [[Order of the Ebon Chalice]] arrives to reinforce the [[Space Marines]] and together push forward, but their advance is stopped by [[Daemon Prince]] [[Lord Gralastyx]] and his [[Chaos Space Marines]] and the [[Imperium]] forces are nearly defeated. [[Saint Celestine]] appears suddenly and fights through the hordes and eventually kills Gralastyx and turns the tide of the battle. She disappears again just as suddenly.

|-

|The "[[Cypher|Voice of the Emperor]]" makes himself known in the Agripinaa Sector, exhorting its inhabitants to rise up against the authority of the [[Administratum]].

|-

|rowspan=3|996.M41

|-

|The [[Iron Warriors]]' [[Fortress World]] of Forgefane is besieged by a tendril of [[Hive Fleet]] [[Leviathan]]. The Iron Warriors welcome the challenge, but are over-matched and within weeks, the last of the world's fortresses, the Ironblood Citadel, falls to the swarms of [[Ravener]]s.

|-

|The Imperium sends operatives from the [[Officio Assassinorum]] to kill the [[Cypher|Voice of the Emperor]]. None return, though one is able to relay a communication describing the target.

|-

|138.997.M41

|rowspan=6|999.M41

|The [[Zeist Campaign]] sees the Imperium take back the worlds they lost in the Tau Third Sphere Expansion. The highly successful Campaign is led by [[Captain]] [[Cato Sicarius]] of the [[Ultramarines]]' 2nd Company, along with elements from at least nine other Chapters and Imperial Guard Regiments. A thrust into the Tau Empire could not be sanctioned however, as the forces were recalled to their other duties.

|-

|[[Justicar]] [[Alaric]] of the [[Grey Knights]] accompanies [[Inquisitor]] [[Ligeia]] on a quest to prevent the [[Daemon Prince]] [[Ghargatuloth]] from returning to the Materium. The Grey Knights are unable to spare more men while deploying their forces to the [[Cadian Gate]] to combat the [[13th Black Crusade]].

|-

|The [[Dark Angels]] trace the Voice of the Emperor to the Agripinaa Sector. They find and destroy a radio beacon in the approximate former location of [[Caliban]].

|-

|010.999.M41

|561.999.M41

|[[Cypher]] eludes [[Belial]] for the third time on [[Piscina IV]].

|-

|718.999.M41

|786.999.M41

|The [[Deathwing]] and [[Ravenwing]] kill [[Inquisition|Inquisitor]] Rasputin while pursuing [[Cypher]].

|-

|3.789.999.M41

|3.978.999.M41

|The [[Armageddon Steel Legion|Armageddon 45th Heavy Artillery]] decimate the Ork hordes of [[Minerva]]. Each shell is inscribed with the name of a soldier or civilian killed at [[Hades Hive]] during the [[Third War for Armageddon]].

|-

|980.999.M41

|The [[Red Corsairs]] emerge from the Maelstrom in force and lay siege to several systems, notably the Chogoris, Kaelas, and Sessec systems. The [[White Scars]] withdraw from the [[Armageddon]] theatre to meet the threat.

|-

|982.999.M41

|3.982.999.M41

|The 56th regiment of the [[Mordian Iron Guard]] put down the [[Komarl Revolt]], and, to ensure future compliance, executes ten percent of the remaining population for forgetting their duty to the [[Emperor]].

|-

|5.985.999.M41

|The Imperial World of [[Cytheria]] defects to the [[Tau Empire]]; a guerilla campaign by several [[Catachan]] regiments critically undermines the Tau's morale.

|-

|986.999.M41

|[[Tech Priest]]s of the [[Adeptus Mechanicus]] discover failures in the mechanisms of the [[Golden Throne]] that are far beyond their ability to repair.

|-

|987.999.M41

|990.999.M41

|Eldar forces from the [[Biel-Tan]] and [[Saim Hann]] [[Craftworlds]] destroy both Imperial and Ork worlds surrounding the Octarius system with the intent of denying bio-resources to [[Hive Fleet Leviathan]].

|-

|6.990.999.M41

|The [[Knights of Blood (Warband)|Knights of Blood]] [[Chaos Space Marines]] attacks [[Ornsworld]]. Imperial Guard reinforcements do not arrive before ninety percent of the planet's population is killed, a cruel repeat of the events of the [[Gothic War]].

|-

|992.999.M41