I M1-M15 - Age of Terra: Humanity Dominates Earth. Civilisations come and go. The Solar System is colonised. Mankind lives on Mars and the moons of Jupiter, Saturn and Neptune.

I M15-M18 - Age of Technology: Mankind begins to colonise the stars using sub-light spacecraft. At first only nearby systems can be reached and the colonies established on them must survive as independent states since they are separated from Earth by up to ten generations of travel.

I M18-M22 - Age of Technology: Invention of the warp-drive accelerates the colonizing of the galaxy. Federations and Empires are founded. First aliens encountered and first Alien Wars are fought. First human psykers scientifically proved to exist. Psykers begin to appear throughout human worlds.

I M22-M25 - Age of Technology: First navigators are born allowing human spaceships to make even longer, quicker warp-jumps. Mankind enters a golden age of enlightenment as scientific and technological progress accelerates. Human worlds unite and non-aggression pacts are secured with dozens of alien races.

I M25-M26 - Age of Strife: Terrible warp-storms interrupt interstellar travel. Sporadic at first, the storms eventually prevent any warp-jumps being made. The incidence of human mutation increases rapidly. Mankind enters a dark period of anarchy and despair.

I M26-M30 - Age of Strife: Human worlds ripped apart by civil wars, revolts, alien predation and invasion. human psykers and other mutants dominate some worlds and these rapidly fall prey to warp-creatures. Humanity is on the brink of destruction.

I M30- present - Age of Imperium: Earth is conquered by the Emperor and enters an alliance with the Mechanicum of Mars. Finally the warp-storms abate and interstellar travel is possible again. The Emperor builds the Astronomican and creates the Space Marine Legions. Human worlds reunited by the Emperor in a Great Crusade that lasts for two hundred years.

II 755.M41 - The Sabbat Worlds Crusade Begins to reclaim Imperial worlds from the foul clutches of Chaos. It is the largest military offensive since the Macharian Conquests. The crusade outlives Warmaster Slaydo, who names the relatively young Macaroth as his successor, an appointment later confirmed by the Departmento Munitorum and the High Lords of Terra Under Macaroth's guidance the crusade continues and the names of many Imperial Guard regiments are entered unto the Hall of Heroes on Holy Terra.

II 762.M41 - The Catachan MXIV Unseen Lurkers, led by Colonel Steel Eye Black, battle against Orks from the Death Skulls clan on the shadow world of Kato. Neither side is able to gain an advantage until Sentinel teams locate and destroy the Orks Stompa factory, hidden in the depths of the Widow Valley.

II 777.M41 - Spearheaded by the Black Legion, Chaos Space Marine forces exit the Warp at the Cadian Gate. Their advance into the Imperium is slowed by the actions of the Cadians. Imperial Fists Space Marines reinforcement arrive and help the Guard drive the renegades back into the Eye of Terror.

II 790.M41 - Forces of the Vostroyan IX, serving under the command of Graf Toshenko, die to a man defending the factory city of Polia against the forces of Tau Commander Brightsword on Nimbosa. Inspired by their sacrifice, the populace refuses to submit to the Tau notion of the Greater Good.

II 845.M41 - The Dimmamak War escalates after Dark Eldar pirates capture Warmaster Ingenus in response, a further forty thousand regiments are raised and all high-ranking Imperial Guard officers are assigned personal bodyguards.

II 857.M41 - A surprise assault by the Eldar of the Saim-Hann Craftworld threatens to annihilate the forces of the Mortant VII 'Headhunters' during the Sacking of Colonia. The Eldar retreat after a single squad of Catachan Devils, led by Gunnery Sergeant Harker, emerges from concealed positions and heavy bolter fire kills the warhost's Autarch.

II 863.M41 - The Cadian 423rd, led by the legendary tank ace Knight Commander Pask, rally to engage rearguard elements of the Adamant Fury Titan Legio during the Saint Cyllia Massacre.

II 870.M41 - In a rare instance where regiments from Attila deploy in force, Mogul Kamir leads a decisive three-year offensive against the Necron Tomb wardens of Loxar IV. The enemy forces are finally defeated during the ill-fated charge of the Lumen Valley, the largest cavalry charge in the Imperium's recorded history.

II 883.M41 - The Cadian 423rd Spearhead the largest armoured assault since the Battle of Tallam. Over eight thousand tank companies and thirty five super-heavy detachments are annihilated during the near-total destruction of a renegade Titan Legio at the Planus Steppes.

II 925.M41 - Waaagh! Grax descends upon the Ryza system. Regiments are raised from all planets within ten light years, including the worlds of Barac, Ulani, Dulma'lin and Catachan. To meet the additional tithe requirements, the world of Dulma'lin drafts four-fifths of its total populace. Commander Mordrid van Hordric finally defeats the bulk of the Orks, decades later at the Battle of Desolation Valley.

II 926.M41 - The Dulma'lin Cleansing: A single regiment of Catachan warriors, led by the bombastic Colonel Straken is the only regiment to survive planetfall on the world of Dulma'lin. Under Straken's orders, the Catachan regiment fight a year-long guerrilla war in the subterranean depths of the planet's caverns, earning a fearsome reputation amongst the Ork tribes.

The decisive moment in the fighting occurs after Catachan souts locate the center of the Ork city in a massive underground cavern known as the Mommothian Vault. Straken personally leads a handpicked team of demolitions experts and infiltrates the Ork settlement. The Catachans' presence is detected on the third day of the operation by a roving pack of Squig-hounds and in the ensuing fight Straken accounts for the deaths of at least thirty Orks and a mob of Killa Kans. The Colonel is seriously injured when he drags Ork Warlord Killzkar into the path of a stampeding Squiggoth which tramples them both into the cavern floor. Straken's men succeed in destroying the Vault's primary support stacks and carry the Colonel's broken body to safety before the entire cavern-ceiling collapses and destroys the Ork settlement.

Imperial Reinforcements arrive two days later, led by a haughty Purbech officer, High Practor Osh'preen. The remaining Ork threat, scattered and leaderless, is exterminated within a week. Osh'preen's report to Segmentum Command Fails to mention the Catachan II's true involvement in the Dulma'lin campaign, citing Straken's regiment as uncouth soldiers, little more civilized than the Orks themselves. Taking complete credit for the cleansing of Dulma'lin. Osh'preen is awarded governorship of the planet as a reward.

The men of the Catachan II are unceremoniously redeployed to the Ulani system. Colonel 'Iron Hand' Straken is tended to by a team of medicae personnel, clinging onto life throughout the journey. He aeakes after extensive bionic surgery to find himself surrounded by the enemy, the Catachan II ever standing by to carry out his orders and win yet another war.

II 927.M41 - The renowned armoured siege units of the Hammeront IV, under command of Grand Marshal Lourgant, are wiped out during the Fallaxian Scourging when an army of Daemons overwhelms the Imperium's forces.

II 928.M41 - The Catachan II assist the Ulani defence battalions in search and destroy missions against Ork Kommandos in the planet's polar mountain range.

II 929.M41 - Such is the delay in transmitting information and updating the Administratum's records, that news of the demise of Hammeront IV regiment fails to reach the Departmento Munitorum and Grand Marshal Lourgant is ordered to lead the liberation of the Abraxis Citadel on Prassium.

II 930.M41 - The Catachan XXIV ' Waiting Death' destroys Krakshull's Orks on Arandra V, luring the entire horde into a booby-trapped ravine with 'Baiter Squads.'

II 931.M41 - The Departmento Munitorum charges the Hammeront IV with desertion and along with Lord General Lourgant, they are all posthumously sentenced to death.

II 932.M41 - Techno Magus Stannum Vir discovers fragments of an STC device on the agri world of Jollov. However, a vanguard tendril of the newly emergent Tyranid Hive Fleet Moloch threatens to consume the world before it can be recovered. At the Techpriest's behest a courageous defense of the planet's spaceport ensues. Elements of Catachan, Mordian, Kanak, Molov, and Agathon regiments die to buy enough time for the Adeptus Mechanicus to flee with the invaluable technological relic.

II 934.M41 - Elysian troops drive off Ork Kaptin Blacklaw and his Freebooterz from the Stranthium Orbital Space Docks, ending a decade long blockade by the alien pirates.

II 935.M41 - The offensive on Bren's World falters when Imperial forces from over two-dozen worlds are unable to take the fortifications at Haven's Spire. The Cadian 12th lead the blitz that finally destroys the Spire following the destruction of several void-shield generators by elite Storm Trooper units.

II 936.M41 - The hive world of Derondii withhold its annual tithes and the Krieg Death Korps are deployed to act as the honour guard of a Departmento Munitorum investigation team After the Imperium officials are hanged, the Krieg deploy in the towering mountains that overlook the primary hive. Several artillery and siege companies begin to bombard the city spires and the inhabitants are mercilessly gunned down as they try to break out from the besieged city. After ten years of relentless shelling, the hive is reduced to naught but rubble and dust, two years after all signs of life from the hive ceased and five years after the hive issued its unconditional surrender.

II 937.M41 - The Cadian 9th devastates Hive Fleet Scarabus at the walls of Fortress Carcasson without loss of a single company.

II 938.M41 - During the Yaquit 27 campaign, Colonel Straken personally leads the Catachan II in the charge at the Battle for Moden's Ridge, exterminating the L'Huraxi invaders despite being outgunned and outnumbered more than ten to one.

II 939.M41 - Ork attacks throughout Segmentum Solar become more frequent. Whilst serving with the 70th Luther McIntyre regiment on the bleak world of B'run, Commissar Yarrick learns the Ork language from a captured greenskin and develops a unique insight into the Ork psyche.

II 940.M41 - The conquest of Atna IV is halted when Imperial forces are unable to take the Palace of Hate. With the arrival of the Catachan XXIII five years later elite sapper units breach the palace walls within the week.

II 941.M41 - The Second War for Armageddon: The Second War for Armageddon begins when Warlord Ghazghkull Mag Uruk Thraka, self proclaimed prophet of the Ork gods Gork and Mork, invades the industrial hive world at the head of the largest Waaagh! ever witnessed.

Commissar Sebastian Yarrick, on Armageddon to assist in the founding of the 4th Armageddon Regiment, recognizes in the Warlord a cunning and drive not encountered before in an Ork . Instead of heeding Yarrick's counsel Herman von Stab, the planet's overlord, banishes 'Old Man' Yarrick to Hades Hive far from the seat of government.

The savage Ork assault sweeps von Stab's forces aside and only upon reaching Hades Hive do the urging tides falter before the well-ordered defenses that Commisar Yarrick put into position. the momentum of the Ork onslaught is stymied during the ensuing battle for Hades Hive, the Ork Warlord being out-smarted at every turn by Commisar Yarrick and the Orks and Steel Legion defenders reach a bloody standstill.

Hades Hive eventually falls to the Ork invasion and Yarrick is grievously wounded by Ghazghkull himself. The Commissar's stoic defense succeeds in delaying the Warlord long enough for reinforcements to arrive and, spearheaded by three Space Marine Chapters, the back of the Ork Waaagh! is broken Ghazghkull flees the world to lick his wounds.

Clining to life, Yarrick is one of the few survivors found in Hades Hive and, soon after his recovery, he is celebrated as the Savior of Armageddon. Without his leadership, the world of Armageddon and its surrounding systems would surely have been lost to the Orks.

II 944.M41 - Commissar Yarrick comes out of retirement and devotes the remainder of his years to hunting down Ghazghkull and ending the threat he poses to the Imperium forver.

II 956.M41 - The Kieldar Rebellion is utterly crushed by the combined forces of the Cadian, Morax, Loriar, Elysia, Catachan, Aegis, Tallarn, Harkoni, Neocassan, Paragon, Vostroyan, Birmingham, Mordian, Jjojos, Pintax, Athanos, K'phrani, Rassiosan, and Bannan regiments.

II 968.M41 - The planet of Khai-Zhan is plunged into rebellion and, led by the Night Lords Traitor Legion, rebels cature every major population center before daybreak. less than on-tenth of Imperial Guard regiments sent to retake Khai-Zhan survive. However, in one of the most brutal urban conflicts in recent memory, the Cadian 122nd and their allies succeed in recapturing the captial city of Vogen. With the world's primary starport secured, the Imperium's forces overwhelm the remaining traitors within a month.

II 975.M41 - The young Ursarkar Creed and his Whiteshield squad are hurried into the five-year Drussite Crusade. By the time the Cadian army celebrates its victory in the blaze of the xeno-pyres. Creed has been promoted to Captain.

II 978.M41 - Whilst in the pursuit of his nemesis, Commissar Yarrick is captured at Golgotha. His personal Baneblade, the Fortress of Arrogance, is destroyed during the fighting. He escapes barely a month later in mysterious circumstances, but the planet of Golgotha and its abhuman inhabitants are utterly destroyed by the Orks.

II 979.M41 - The Tau Empire expands into the Imperium's territory and many worlds defect, initiating the protracted Damocles Gulf Crusade in which notable victories are won by the regiments of the Brimlock Dragoons.

II 980.M41 - Chaos Space marine Lord Brule and his renegades are destroyed on Treconondai by a combined force of the Cadian 8th and Terrax Guard.

II 983.M41 - A Hrud migration is halted due in no small part to the courageous efforts of the Cadian 8th, a campaign in which the tactical abilities of Ursarkar Creed proved instrumental.

II 988.M41 - The Damocles Crusade is abandoned due to the emergent threat of Tyranid fleet Kraken. The Imperium's forces are redeployed to support other beleaguered worlds.



Source Information

I - "The Horus Heresy Collected Visions"
II - "Codex: Imperial Guard 5th Edition"