Historian's Note: All dates relating to the Great Crusade and the Horus Heresy are only approximations. Imperial records from this time are too fragmentary to be wholly reliable.

• c. M30-M31 Eldar Exodus - Sensing the end of their civilisation is approaching, a small portion of the Eldar race combine and modify their starships into Craftworlds, gigantic living vessels that are able to accommodate an entire planet's population of Eldar. One by one the Craftworlds begin to escape the murderous, hedonistic corruption that now dominates the Eldar empire's homeworlds. Hundreds of Craftworlds sail into the depths of space in search of the relative safety of the void from the catastrophe that their Farseers claim will soon consume the Eldar people.
• c.M30-M31 Birth of Slaanesh and formation of the Eye of Terror - The great interstellar civilisation of the Eldar falls into decadence and depravity. A new Chaos God is born from the depths of their hedonistic excess in the Warp -- Slaanesh, the Dark Prince of Pleasure. The psychic violence of his apotheosis consumes the worlds at the heart of the Eldar Empire in what is now the Segmentum Obscurus of the Imperium of Man. A vast section of realspace in this region is plunged into the Warp. Its wake forms the permanent Warp rift later known as the Eye of Terror amongst Mankind.
• c. M30 End of the Age of Strife - The Warp Storms that have made interstellar travel and communications through the Immaterium impossible for the last 5,000 Terran years of the Age of Strife finally abate after the birth of Slaanesh within the Warp and the Fall of the Eldar.
• c. M30 The Primarch Project - The 20 superhuman Primarchs are genetically engineered by the Emperor of Mankind in his great gene-laboratories deep beneath the Himalazian (Himalayan) Mountains on Terra, beneath what will become the Imperial Palace. As His greatest creations near completion of the gestation cycles, the Chaos Gods penetrate the confines of the Emperor's laboratories despite his psychic wards and seize the nascent Primarchs from the Emperor's sanctum, scattering them through the Warp across human space while still in their gestation capsules.
• c. M30 The Unification Wars - During the turbulent era known as the Age of Strife, the Sol System and the nearby star systems that had been colonised by humanity during the Dark Age of Technology were effectively cut off from interstellar travel or communication with each other due to the massive Warp Storms that swept the galaxy as the Immaterium was roiled by the millennia-long gestation of the Chaos God Slaanesh and the turbulence that marked the decay of the Eldar empire before the Fall. During this dark time, Terra sometimes held sway over the Sol System, while at other times the rulers of Mars or Luna were dominant. The different worlds found themselves constantly at war. During this long, 5,000-year-period of anarchy, fear and violence, Old Earth's once unified planetary government had completely broken down and been divided into dozens of warring states of so-called techno-barbarians. Continuous warfare raged across the surface of Terra for 2500 years, beginning in the late 27th Millennium. Little remained of the once sophisticated civilisation of Old Earth's glorious past as the center of a growing human interstellar civilisation marked by advanced science, high culture and wondrous technologies. Techno-barbarian warlords and their warrior hordes continuously fought over the planet, which had become little more than a massive battleground for their wars of attrition. They made use of chemical, biological and even thermonuclear weapons of mass destruction, and slowly transformed the cradle of Mankind into a battered, post-apocalyptic wasteland across most of its scarred surface. This was a dark period for the people of Old Earth when they were dominated by brutal rulers and despotic tyrants. It was against this backdrop of oppression, violence and casual brutality that the Emperor of Mankind first revealed himself to the people of Terra. In secret, he had been planning for this moment in history for millennia, ever since the Age of Strife had fractured what remained of the ancient human federation. With his massive army of genetically-enhanced warriors who comprised the first units of the Imperial Army and would serve as the prototypes for the later development of the Space Marines, the Emperor began his conquest of Terra with the intent to reunite the warring nations into a unified planetary government and then use Terra as the springboard from which to begin his reconquest of the galaxy under the aegis of an Imperium of Man dedicated to the Imperial Truth of progress and reason. Brutal rulers such as the warlord Kalagann of Ursh, Cardinal Tang of the Yndonesic Bloc, and the most infamous of all, the half-mad, half-genius Nathaniel Dume, the Tyrant of the Pan-Pacific Empire, would all fall by the wayside. Once unleashed, the armies of the Emperor swept all before them like wheat before the harvester's scythe until all the techno-barbarian warlords had either been conquered outright or had agreed through diplomacy to become subservient to the Emperor's will. During this time the Emperor created a number of military organisations, such as the Imperial Army, which would become the nucleus of the armed forces that would support his Legiones Astartes and his reconquest of the human-settled galaxy. Amongst the early Imperial Army units that saw action during the Unification Wars were such venerable regiments as the Geno Five-Two Chiliad, which would become one of the oldest and most respected regiments within the Imperial Army. Like many of these early regiments, the geno-soldiers were created through the use of some of the Emperor's sophisticated genetic engineering techniques, developed in his laboratories beneath the Himalayan Mountains and on Luna. The most elite of this first generation of genetically-engineered supersoldiers were known as the Thunder Warriors, men who were physically stronger and more formidable in combat than even the later Space Marines, though they were engineered to be vicious killers and lacked many of the more noble aspects of the Astartes as well as their tremendously long lifespans. The Thunder Warriors were engineered to be the means to an end and were never intended to be integrated into the Emperor's new realm after Unity had been achieved. Through genetic engineering and selection the standard geno-soldiers displayed many of the characteristics of the perfect human warrior -- they were physically more resilient, stronger and capable of taking more damage than any of their unaltered techno-barbarian foes. These early genetically-engineered Imperial Army regiments would go on to continue serving the Emperor after the conclusion of the Unification Wars. These regiments would eventually be referred to as the Old Hundred, and would form the core of the initial military force that embarked upon the Emperor's galaxy-spanning Great Crusade in the early 31st Millennium beside his newly created Space Marine Legions. The Emperor accepted the deaths of the many innocents that resulted from the conquest of Terra with great remorse in order to achieve the greater good of unifying humanity and protecting it from the manifest predations of the Warp and predatory xenos of the galaxy. Unimaginably large, full-scale battles during the Unity campaign would last for weeks on end, with body counts in the millions that sundered mountains and split entire continents. Future Imperial scholars would later dismiss these victories as lurid hyperbole, refusing to believe that such clashes of arms could possibly have been fought, but indeed they were. The Imperial historical chronicles tell of the last battle of the Unification Wars, known as the Battle of Mount Ararat, which was fought in the Kingdom of Urartu. During this final battle the remaining Thunder Warriors were slain to a man. The chronicles recorded that the famed Thunder Warrior Arik Taranis, known as the "Lightning Bearer," raised the Banner of Lightning at the final declaration of Unity which established the rule of the Emperor of Mankind over the entirety of Terra before dying of his wounds. It was a measure of the Thunder Warriors' heroic sacrifice that they had all died to win the last and greatest victory for the Emperor. Unfortunately, this heroic version of events was completely false. The Thunder Warriors had not died to a man during the final battle of the Unification Wars. They had been brutally culled from existence by the Emperor's own servants on his orders. The Thunder Warriors had been betrayed by their own creator, a terrible secret skillfully concealed from the people of the Imperium for more than 10,000 Terran years. When the Unification Wars were complete at the end of the 30th Millennium, the Emperor forged a new unified planetary government for Terra under his leadership.
• c. M30 Sa'afrik Liberation - The XII Legion's first recorded engagement was during the Sa'afrik Liberation of the Unification Wars where they served as a spearhead of shock troops, mounting direct annihilation assaults on enemy forces, both in open battle and fortified positions. They proved able to carry the attack despite their then-relatively small numbers by sheer courage and the fury of the violence they could unleash. After its initial battles in the conflict the nascent XII Legion seems to have been largely held in reserve by the Emperor during the later Unification Wars.
• c. M30 Pacification of the Boetian Lowlands - When the XV Legion (Thousand Sons) was created they were used to quell the few pockets of isolated resistance to the Emperor's rule that remained on Terra during the Wars of Unification. Boetia was a nation that had existed since the Age of Strife and was chiefly known for holding out against the Unification for a considerable period of time until it was finally forcibly incorporated in the newborn Imperium. The ruling family, the Yeselti, attempted to stubbornly cling to power, forcing Imperial Army forces to invade their province the Astartes of the XV Legion were sent in to finally crush any further resistance in a brilliant campaign that lasted only six weeks. Shortly after achieving this objective, the XV Legion was formally named the Thousand Sons by the Emperor Himself and was sent out into the galaxy as part of his Great Crusade. This particular conflict holds the distinction of being the final campaign of the Unification Wars that took place during the Great Crusade.
• c. M30 Conquest of Galaspar - This was the first major independent campaign conducted by the newly-dubbed Death Guard after Mortarion took charge of the XIV Legion. The conquest of the non-Compliant Hive World of Galaspar remains one of the most remarkable and brutal victories of the Great Crusade's course through the near reaches of the Segmentum Pacificus. When the Imperial support fleet arrive they were horrified by the aftermath of the slaughter. The billions of humans "liberated" by the Death Guard were almost childishly eager to accept the Emperor's servants and adopt their ways. In the wake of the conquest Galaspar, the cluster of worlds quickly capitulated with terrified speed, all willing to submit to Imperial Compliance under any terms as long as they were spared the reaper's scythe.
• c. M30 Kajor Compliance – On Kajor during the Great Crusade, the Death Guard Legion encountered a warrior race of humans that had fallen to barbarism. Extensive orbital surveys detected no trace of advanced technology, yet it took the XIV Legion nearly six months to bring Kajor to submission. Though the Kajori were savages, armed with little more than blades and crude flintlock carbines, this feral race was able to hold the Death Guard at bay. They were able to do so because they possessed fell powers and unseen allies. In quieter moments, Mortarion still thought of the Kajor campaign and shuddered. Mortarion would later recount the tale of this campaign during the Council of Nikaea as one example of many why he took a personal stance against sorcery and the use of psychic abilities.
• c. M30 Krypt Prosecution – The Compliance of Krypt was a relatively short campaign conducted during the Great Crusade by both the Death Guard and the Luna Wolves Legions against the Orks upon the frozen plains of the world of Krypt. Fighting together for more than a week across the frozen surface of the planet, the Space Marine Legions turned the blue ice dark with xenos blood. Battle-Captain Nathaniel Garro and his 7th Great Company were known to have fought alongside the Luna Wolves' Captain Garviel Loken and his 10th Company during this action.
• c. M30 Pacification of the Cephic Hives - The Pacification of the Cephic Hives was another early campaign of the XII Legion during the latter days of the Unification Wars. The Emperor Himself dubbed the XII Legion his "War Hounds" at this time as a tribute to the savage and tenacious way they fought to pacify the narco-sprawls of the Cephic Hives.
• c. M30 Cerberus Insurrection - The newly dubbed War Hounds were tasked alongside the Terran XXII Dracos Regiment of the Imperial Army to subdue the asteroid prison colony of Cerberus which had risen up in anarchic revolt in a state of near continuous rioting and mob violence. Initial attempts to impose order by Terran troops had been thrown back in disarray as it became apparent that among the insurrectionists was a renegade cadre of outlawed Thunder Warriors, long believed dead, calling themselves the Dait'Tar. With many of the Space Marine Legions already assigned to the first Expeditionary Fleets of the Great Crusade and en route to the stars, the Emperor Himself dispatched his War Hounds to Cerberus with explicit instructions to reclaim Cerberus colony and carry the Emperor's wrath to those that had defied Him.
• c. M30 First Pacification of Luna - This early Imperial campaign was the first operation mounted by elements of the early Space Marine Legions beyond the skies of Terra. Luna was the bastion of a conglomeration of resurrectionist gene-cults whose members believed that human nature was both fractal, fractured and transcendent. Each of these Selenar gene-cults clung to a different set of archetypes. Every cult member was a product of creation by the Selenar gene-wrights according to formulae crafted in the Dark Age of Technology. The Selenar returned the Imperial entreaties for alliance with silence. So it was that the Emperor finally ordered Luna to be pacified by the sword, their superstitious beliefs cast down before the Imperial Truth and their gene-craft yoked to the needs of the Imperium. To this task the Emperor set the three of his newborn Space Marine Legions most suited to this purpose on what some Imperial chroniclers name as the first true battle of the Great Crusade. The combined force of the VII, XIII and XVI Legions (later named the Imperial Fists, Ultramarines and Luna Wolves) lifted from the surface of Terra in a scattering of rocket flame. The as yet unnamed XVI Legion had been chosen to serve as the Space Marine force's vanguard, and had brought its full strength to bear. Within six hours of the first shot being fired, Luna had been pacified and brought into Imperial Compliance, the first off-world conquest of the Imperium of Man. Faced with annihilation, the surviving Selenar cultists bent the knee instead, their surrender communique transmitted to Terra calling for the Emperor to "call off his wolves." As for the XVI Legion, they had earned their name -- the Luna Wolves.
• c. M30 The Treaty of Mars (Treaty of Olympus) - The Emperor of Mankind travels to Mars and lands his flagship in the caldera of the great Martian mountain of Olympus Mons where he is welcomed as the Omnissiah, the living embodiment and avatar of the Machine God by the Cult Mechanicus. The Emperor convinces the leadership of the Mechanicus to forge a political alliance with the Imperium of Man in an agreement known to history as the Treaty of Mars and the Treaty of Olympus within the Mechanicus. In return for granting the Imperium the use of Mars' massive manufactorums, the orbital shipywards of the vast Ring of Iron and the military strength of its Titan Legions and the technological and scientific skills of its Tech-priests, the Emperor guarantees that the Mechanicus, now known as the Adeptus Mechanicus, will remain politically autonomous within its own territories and will be exempt from the atheistic doctrines of the Imperial Truth so that the Cult Mechanicus can continue its ancient worship of the Machine God. This agreement, known as the Treaty of Mars (the Treaty of Olympus to the Mechanicus), marks the true foundation of the Imperium of Man in the alliance between Terra and Mars. The Imperial Aquila chosen by the Emperor as the symbol of his new Imperium is altered to possess two heads, one representing Terra and the other Mars.
• c. M30 The Gorro Hollowing - Within the Telon Reach was an Ork empire that rivalled that centred on Ullanor, and at its heart was the scrap world of Gorro. The Ork tech-caste, the Mekboyz, dominated the Orks of Gorro and had made the world their own. The Emperor decreed that Gorro must be destroyed. When a thousand-strong fleet of warships dropped out of the Warp above Gorro it was the Emperor Himself who gave the order to begin the assault. Horus, ever the dutiful and favoured son, stood at the Emperor's side and watched as tens of thousands of assault craft spread out from the fleet. In the vanguard was the Emperor and by his side was Horus and a guard of black-armoured Justaerin Terminators from the Luna Wolves' 1st Company as well as the golden-clad warriors of the Legiones Custodes. As the Space Marines attacked, the Ork resistance they faced was near overwhelming. The Orks of Gorro were huge and augmented with scavenged bionics. At the height of the battle, the fury of the Orks split the Emperor from his guards. Alone he slew hundreds of them until a blast from an Ork plasma weapon weakened his defences and one of the Ork leaders seized him. The creature's strength was so great that it took hold of the Emperor and buckled his armour. As the creature's grasp closed to throttle the Master of Mankind, Horus stormed through the press of battle and cut the Ork's arms from its body with a single blow. Together father and son led their forces in the defeat of the great Ork empire of Gorro.
• c. M30 Castigation of Terentius - When the forces of the Great Crusade first entered the Ordoni Cluster, they encountered the formidable warlord Vatale Gerron Terentius. Observing the forces arrayed against him, Terentius was forced to take the path of survival and surrendered to the Imperium. The Imperium had need of men like Terentius, and the Great Crusade gave him opportunities and riches such as he had never dreamed. Given a small fleet of warships and a handful of Imperial Army regiments, Terentius grew his forces by conquest. For five decades he rose in power and reputation, conquering worlds around the Halo Stars in the name of the Emperor. At the height of his powers, he had the ear of Malcador the Sigillite and the countenance of several Primarchs. When he finally turned against the Imperium, many were shocked. Terentius began to conquer already Compliant planets, his contra-Crusade conquering system after system in his own name, rather than for the sake of all Mankind. Soon he had entire fleets of warships, tens of millions of soldiers and the loyalty of a hundred human-settled worlds. Ringed by fortress worlds, this rebel human empire began to eat up Imperial worlds around the Halo Stars. The Imperium responded by sending Horus and his Luna Wolves Legion to not only break the Renegade but to demonstrate to any others who harboured similar ideas within the Imperial forces the inevitability of a betrayer's defeat. Horus elected to not only use his Legion to complete the task at hand but sent personal requests to his brother Primarchs for support which saw substantial strength from the Night Lords, Iron Hands, and the Alpha Legion joined to the might of the Luna Wolves. Soon the rebels of Terentius's realm were slaughtered, their cities smashed to dust, and his homeworld's very air laced with toxins. Once the castigation was complete, Horus sent the gold-dipped skull of Terentius to Terra with the ironic warning carried on the lips of the messenger who bore it, "So perish all traitors."
• c. M30 Fall of Reillis - During the first thirty years of the Great Crusade, at the fortified city of Reillis, a human settlement unwilling to accept Imperial Compliance, the defenders used secret tunnels to infiltrate behind the besieging Imperial army and hundreds of enemy shock troops swamped the Imperial command encampment. Unprepared and unarmoured, the Emperor and Horus fought back-to-back until a plasma blast stunned Horus and sent him staggering to the ground. The Emperor stood over the fallen Primarch and refused to give ground until reinforcements arrived to drive their attackers back. The Emperor had returned the favour of his son saving his life on the Ork world of Gorro. This incident helped to forge an unusually close bond between the Emperor and his gene-son, closer than that between any of the other Primarchs and their father.
• c. M30 Nove Shendak Campaign (Eight-Two-Seventeen) - Early in the Great Crusade, the War Hounds Legion had found three star systems under their thrall, and had proceeded to burn them out of their colony nests and chase them back towards their homeworld. But on their cradle-world of Nove Shendak the XII Legion had to their immense surprise discovered humans. Nove Shendak was a world inhabited by worms; giant xenos creatures who were both intelligent as well as hateful. Their weapons were filaments, metal feathers that they embedded in themselves to conduct potent bioelectrical energies out of their bodies. The surface of the world would roil with these filaments before the worms broke out of it almost at the Imperial attackers' feet. The War Hounds, alongside their fellow Astartes Legion the Iron Warriors, and a large contingent of Imperial Army soldiers were charged with exterminating the worms and liberating the humans of Nove Shendak. Fighting the worms was next to impossible as the lunar tides dragged the mud oceans to and fro across the jagged stone continents, making the ground very unstable. When the worms finally emerged to assault their attackers, they met the Emperor and his War Hounds. Though the casualties were horrendous, the War Hounds eventually emerged triumphant and the worms of Nove Shendak found only extinction. The people of that world inherited the planet and became fervent supporters of the Imperium.
• c. M30 Golgothan Slaughter, Siege of Sarum - The first known target to suffer the wrath of the World Eaters Legion after their Primarch Angron took command of the XII Legion sometime in the last two centuries of the 30th Millennium was the stellar wasteland of the Golgotha Secto. The Golgotha Sector was sited near the galactic core in the Segmentum Ultima close to the realspace Warp rift known simply as the Maelstrom. Sarum was being besieged by the Abhuman empire known as the Brotherhood of Ruin who wished to take the Mechanicum's technological secrets for themselves. The Tech-priests of the Mechanicus' Redjak Cult had endured alone for ages, subjected to the privations of raiders and enemies all around them, with only intermittent contact with distant Mars and the Forge World Anvilus, requesting aid that had never yet managed to reach them. The World Eaters arrived as their saviours, smashing into the heart of the besiegers. With the Siege of Sarum broken, the Redjak Mechanicus swore to Angron and his Legion directly many oaths of fealty and entered pacts of mutual protection and support. This provided the World Eaters and their Techmarines with a ready source of resupply and armament far outside the Imperium's inner sphere.
• c. M30 Liberation of Alpha Shalish - It was during the XII Legion's campaign in the Golgotha Sector that the World Eaters' 203rd Expeditionary Fleet encountered the Lacrymole-infested world of Alpha Shalish. Remembrancers and Imperial artist-scribes of the 203rd Expeditionary Fleet recorded the auspicious events surrounding the liberation of the xenos-controlled world of Alpha Shalish. The Imperial forces, spearheaded by World Eaters Space Marines, burst into the mounded Lacrymole cities with righteous fury, cleansing the planet of their foul, man-eating kind with extreme prejudice.
• c. M30 Ghenna Scouring - This was an infamous campaign conducted by the World Eaters against the world of Ghenna, where the entire planet's population was butchered in a single night of bloodshed. The World Eaters were censured by the Emperor and commanded to cease the implantation of the Butcher's Nails cortical implants. Angron paid little heed to the Emperor's dictates and ordered the work of his Legion's Techmarines to continue until all of his Astartes had been implanted.
• c. M30 Night of the Wolf - The Night of the Wolf is a little known incident that occurred shortly after the massacre of the entire planetary population of Ghenna. The Primarch Leman Russ had been charged by the Emperor to take his Space Wolves Legion to Ghenna to bring the World Eaters to heel. The two Legions met at Malkoya, on the fields beyond the dead Ghennan city of that same name. The World Eaters, battered and bleeding from Ghenna's Imperial Compliance campaign, formed ragged lines before the assembled Space Wolves Legion. Angron refused to recognise his brother's authority, and warned the Wolf King to depart before the situation became something that he would regret. Russ informed Angron that the implantation surgeries must end, for the Emperor Himself had deemed it so. The massacres of newly discovered human worlds were to end with the fall of Ghenna. The World Eaters were to submit to the Space Wolves as their escorts for their Legion's return to Terra. Once they reached the Imperial Palace, everything would be done to remove the parasitic Butcher's Nails implants from the World Eaters' minds. Angron was not amused by Russ' implied threats. No one ever saw who fired the first shot. In the decades after, the World Eaters claimed it came from the Space Wolves' lines, and the Space Wolves claimed the same of the XII Legion. Without either Primarch giving an order, the two Space Marine Legions fought.
• c. M30 Supression of Kernunnos - This was in Imperial Compliance carried out by the Wolf Lord Bulveye of the Space Wolves 13th Company and the Imperial Army contingent known as the Arcturan Dragoons against the world of Kernunnos located in the Lammas Sector. When the 954th Expedition came to the Lammas Sector, they brought good tidings and Imperial Truth from the Emperor. But despite the Wolf Lords open handed gesture of peace, the twelve ruling self-styled Tyrants of Lammas spat upon his gesture of peace and unity. Seven years later, their fleets lay broken and their armies scattered. The Tyrants were stripped of their position of power and all their pilfered wealth would be used to help rebuilding what was lost, and ensure that the worlds of the Lammas Sector became prosperous and stable members of the Imperium.
• c. M30 First Kobolt War, Razing of Thuyela - The 40th Expeditionary Fleet was an expeditionary force during the Great Crusade that was shadowed by an Astartes complement made up of the Space Wolves' 3rd Great Company ("Tra" Company). When the 40th Expeditionary Fleet encountered a race of humanoid xenos in Kobolt space who were lethal and proud, and had no interest in human affairs. The xenos' base of operations was a great transparent vessel that sparkled as if it was made of glass, and so was nicknamed by the Imperials "Scintilla City". This vessel was in actuality an Eldar Craftworld, and was called Thuyela in the Eldar Lexicon. True to their capricious nature, the Eldar of Thuyela attacked the 40th Expeditionary Fleet without apparent reason or explanation, and managed to fight the Imperial fleet to a standstill. Fleet commanders called for the help of the Space Marines. An unrecorded number or Great Company of Space Wolves Astartes answered the call and quickly overcame the xenos. As "Scintilla City" shattered around them, the desperate Eldar realised that all would be lost if they continued to fight, and the xenos attempted to plead for terms. Imperial commanders involved in the action might have been content to naively negotiate a surrender, but the Space Wolves were not. Thuyela was sacked and its people slaughtered by the Space Wolves. It was so completely destroyed that there was nothing left for the Imperial forces to recover or plunder. The fate of Thuyela's survivors, if any, is not recorded in Imperial records.
• c. M30 Second Kobolt War, Suppression of the Olamic Quietude - During the Second Kobolt War, the 40th Expeditionary Fleet met up with the Space Wolves near Gogmagog Beta, pressing fruitlessly into the territory of the cybernetic Abhumans called the Olamic Quietude. They were a technologically advanced cybernetic human civilisation that had been founded during the Dark Age of Technology and had survived through the long years of the Age of Strife. Over fifteen thousand standard years, the Quietude had survived by merging themselves so completely with their advanced technology -- as a result of possible xenos influence -- that there was little left of them that could be considered truly human. The 40th Expedition grudgingly called for the aid from the Space Wolves' 3rd Great Company ("Tra" Company) to assist in the assault on the Quietude's homeworld. The combined Astartes and Imperial Army force that brutally eradicated the Quietude and purged all trace of their presence from the galaxy.
• c. M30 Pacification of Necromunda - The Imperial Fists won a major victory against the Orks upon the ash wastes on the Hive World of Necromunda. The Hive Lords consented to recruits being drawn from their population in gratitude and a Fortress-Chapel was duly consecrated, but the Imperial Fists continued to refuse to accept any special rights on the worlds where their Legion recruited. Throughout the Crusade they refused to garrison or claim tithes of newly conquered worlds, instead opting to remain a military unit with none of the responsibilities that came with having a homeworld.
• c. M30 Subjugation of Sarosh – Shortly after their entry into the Great Crusade the 4th Expeditionary Fleet of the Dark Angels reached the orbit of the planet Sarosh (officially codified as Sigma Five-One-Seven). The Saroshi (without mentioning it to the Imperial expedition) secretly worshipped Chaotic entities in the Warp they called the Melachim, and saw the anti-religious stance of the Pre-Heresy Imperium's Imperial Truth as unsuppressed evil. Unknown to the Dark Angels, the Saroshi had secreted a nuclear device aboard their shuttle, intending to assassinate the fleet's entire command structure, including Jonson; however, Luther and a junior Librarian named Zahariel managed to eject the shuttle into space, causing only minor damage to the flagship. After this incident, Luther, Zahariel and five hundred other Dark Angels were sent back to Caliban in disgrace, for allowing an enemy to get a nuclear device aboard the Primarch's flagship, to oversee the recruitment of new Space Marines into the Legion from the Calibanite population.
• c. M30 Compliance of Byzanthis – A Dark Angels’ Expeditionary Fleet, under the command of Chapter Master Merir Astelan discovered the far flung world of Byzanthis during their exploration of system DX-619. Another Dark Angels’ fleet, under the command of Chapter Master Belath, joined Astelan's only two weeks earlier in the Calcabrina System, on orders from the Lion, that Belath add his forces to the expedition. Astelan advocating making a peaceful overture to the planet’s locals in order to foster good relations. Belath advocated a more aggressive approach and to subdue the planet through force of arms. Chapter Master Astelan and one of his commanders agreed to meet the Council in their chambers and explain their purpose. Ten massively armoured Terminators teleported into the chambers and opened fired on the startled delegates, massacring a good portion of their number. Forcing his hand, Astelan reluctantly ordered the assault. He warned his younger counterpart that the blood of all who died on Byzanthis would be on his hands, and that he would not let his actions go unpunished. The younger Chapter Master merely dismissed the senior commander’s threats and proceeded to inform Astelan that he had already sent word to Caliban of what had occurred on Byzanthis and that he would soon learn the consequences of disobedience.
• c. M30 Assault on Dulan - This was a joint Imperial Compliance carried out by both the Space Wolves and the Dark Angels Legions. The Tyrant of Durath had personally insulted the Emperor, sacrificing thousands of Imperial priests to his patron Daemon, and both Primarchs Leman Russ and Lion El'Jonson desired the honour of slaying this heretic. The Tyrant Durath insulted Russ, causing him to demand the right to lead the attack on the fortress. Johnson ignored him and led his own carefully planned attack instead, killing the Tyrant personally. After the battle Russ confronted and attacked Johnson, and the two dueled for a day and a night. Russ eventually stopped attacking, seeing the humor of the situation, at which point Johnson knocked him unconscious. Now he considered honour to be satisfied. The prostrate Russ was carried from the fortress by his men and, when he regained consciousness, the Dark Angels had already departed to fight in the Alisore campaign. Russ swore he would avenge the stain on his honour and, to this day, whenever the Space Wolves and Dark Angels meet, one of their number is called upon to refight the ancient duel of the Primarchs in order that honour may be satisfied.
• c. M30 Siege of Barrakan - This was an Imperial Compliance carried out by the Dark Angels during the Great Crusade against the Orks on the world of Barrakan. A notable campaign of this Compliance action was the defence of Firebase Endriago. A Chapter of the Dark Angels had been cut off by the Greenskins and trapped at the firebase for 18 months. By the end, the beleaguered Astartes were fighting off the alien assaults with fists and pieces of sharpened steel scavenged from bombed-out strongpoints, but through it all Brother Nemiel had never wavered.
• c. M30 Proximan Rebellion - The Proximan Rebellion is one of the earliest recorded engagements of the as-yet unnamed III Legion. Assigned to the Imperial Compliance ceremonies and as the Emperor's honour guard for Proxima's formal accession into the Imperium, an insurrectionist trap was sprung which resulted in the III Legion's XVI Cohort (Chapter) fighting and dying to the last warrior alongside the Legio Custodes, never giving ground during the insurrectionist surprise attack on that world's ceremonial plaza. By their sacrifice was the wounded Emperor, who had suffered injury through the use of a Vortex weapon by the enemy, bought time to recover and fight his way clear of the Proximan insurrectionists' trap. In recognition of this sacrifice, the standard of the Palatine Aquila so fiercely fought for that day was given to the Astartes of the III Legion by the Emperor's own hand, to be their relic ever after, along with the right to end the Proximan revolt by Exterminatus and so repay the blood that was owed them.
• c. M30 Defence of Tranquility - The Defence of Tranquility was a protracted and vicious engagement fought by the Emperor's Children on the periphery of the Dalinite Nebula region during the early phase of the Great Crusade's progress into the Galactic East. Under the overall command of Horus of the Luna Wolves Legion, several Imperial Expeditionary Fleets were combined to prosecute a campaign to purge the Dalinite Nebula. Amongst these Imperial forces were the Emperor's Children, although at this time their fighting strength was still very limited, comprising a single Cohort of barely 500 warriors. Nevertheless, the Emperor's Children were given the important role of securing the world of Tranquility on the trailing edge of the Imperial advance. Outmatched by the numbers of xenos committed to the assault, the Emperor's Children were forced to make a tactical withdrawal into the surrounding maze of Tranquility's fissures and stacks, although in retreat the Emperor's Children were far from beaten. In the end, the III Legion emerged triumphant, annihilating their xenos enemies.
• c. M30 Extinction of the Katara - The xenocide of the alien Katara was a brutal campaign of extermination carried out against this insular Abhuman civilisation that had evolved in the Kenuit System during the Age of Strife. Lieutenant Commander Abdemon ordered the invasion of the largest Kataran city-complex, commencing with an orbital bombardment. The skill in which the Kartarans wielded their weapons was dazzling even to the Emperor's Children. Katara's diplomatic representatives came forward again after hundreds of their warriors had died in their seemingly insane, staggered attacks and requested to meet once more under truce. The Kataran diplomat brought a proposal: let the war be decided by a chosen champion from each side. The Emperor's Children emerged triumphant. The Kataran representatives ordered that all should know that their people had been defeated by an enemy of equal honour but superior arts. The order given, the Kataran leaders fell on their own swords before the Emperor's Children. Across all their domains every member of the Katara followed their leaders in death and the Kataran cities became massive tombs.
• c. M30 Praxil Compliance - The Praxil System was settled by humanity in the distant past and had remained isolated for millennia. Bringing Praxil into Imperial Compliance would bring the Imperium great renown, this formidable civilisation refused to bend the knee to the light of the Imperial Truth, and instead were prepared to fight to maintain their independence. Their warfleet was formidable, and managed to push back the initial invasion of the Imperial Expeditonary Fleet. But if the Praxil warships proved formidable, their warriors proved to be downright deadly. The Imperium wanted Praxil's wealth and resources to harness to the needs of the Great Crusade, and so the securing of Praxil fell to an Army Group-sized force of the Emperor's Children, supported by selected elements of the Imperial Army and the forces of the Mechanicum. A representative of the War Council of Terra observed that the Emperor's Children's Lord Commander Iddinam, who was charged with the command of the Praxil Compliance, would never willingly admit that he needed assistance, and therefore issued a request to Terra for reinforcements. Soon elements from the Blood Angels Legion under the command of Chapter Master Raldoron and Marshal Cazimus of the Imperial Fists arrived in-system to augment the beleaguered Imperial forces. Despite his misgivings and slight to his personal honour, the Lord Commander accepted his cousin Legions' assistance and immediately drew up plans for prosecuting the second offensive against the Praxil. Utilising the strength of the Blood Angels and Imperial Fists Legions, the Emperor's Children launched a successful second offensive against the Praxil that soon saw an Imperial victory. When the Imperium claimed its victory, however, Lord Commander Iddinam refused to acknowledge his role in effecting the Compliance of Praxil, and would later have a hand as a prime conspirator of his Legion's treachery during the Istvaan III Atrocity.
• c. M30 Compliance of Justice Rock - This was the Iron Warriors Legion's first Imperial Compliance campaign that was conducted against the world of Justice Rock and the heretical Black Judges. The newly inducted Astartes recruits from the Iron Warriors' homeworld of Olympia acquitted themselves well and their triumphant return was celebrated in the famous Palimodes Fresco, now known only through fragmented holo-recordings.
• c. M30 Pacification of Schravaan - This was a joint Imperial Compliance action conducted by the Emperor's Children, Iron Warriors, Imperial Fists, and the Luna Wolves Legions against the xenos Badoon on the world of Schravaan. The Iron Warriors won a great victory when they stormed the final refuge of the Badoon. They breached the defences and held while the other Legions carried the city beyond. During the following victory feast, Horus proclaimed Perturabo the greatest master of siege warfare in the Great Crusade. Fulgrim then inquired to his brother Rogal Dorn whether he thought even the defences of the Imperial Palace could resist the Iron Warriors, in which Dorn replied that he regarded the defences as being proof against any assault if well-planned. Perturabo flew into a rage and unleashed unfounded accusations against his brother. After this the two rarely spoke, and neither of their Legions served in the same campaign for the remainder of the Great Crusade.
• c. M30 WAAAGH! Mashogg - In one famous instance, a joint Imperial Compliance campaign was conducted by the Iron Warriors, Space Wolves and White Scars Legions against the Greenskins. Legends record that it was the Primarchs Leman Russ and Jaghatai Khan who routed the Orks of Overdog Mashogg's WAAAGH!, while Perturabo was featured only as the "comrade" who calculated the optimum way to bypass Mashogg's low orbit defences.
• c. M30 Compliance of the Araaki Spiral - A joint Imperial Compliance campaign was conducted by the Iron Warriors, Imperial Fists, Dark Angels and White Scars Legions in a region of space known as the Araaki Spiral. The Araakites were well-versed in the art of building fortresses, and their strongholds were dug deep around narrow passes, remote hilltops and natural barriers in the landscape. Once again, the Iron Warriors were sent to a resistant star system to conduct brutal siege-warfare against formidable fortress-builders. It would take many years for the IV Legion to regain its former strength from the losses sustained during the drawn-out war of attrition that its Astartes suffered in the Araaki Spiral. In the wake of the inevitable Imperial victory, great works of art and heroic verse were composed, celebrating the courage of the other Space Marine Legions, but nowhere in the reams of poetry and artwork were the grim labours of the Iron Warriors judged worthy of note.
• c. M30 X173 Plural Xenocide - This was an Imperial Compliance campaign of the Great Crusade that was carried out jointly between the White Scars Legion and the 40th Expeditionary Fleet's Imperial Army component made up of the genetically-enhanced soldiers of the G9K Division Kill upon the world designated X173 Plural. This campaign against unknown xenos was fought over a period of six months, in which the troops of the G9K came to admire the focus, dedication and mercilessness of the White Scars.
• c. M30 Compliance of Darrowmar (Unknown Date.M30) - The Night Lords fought alongside the Luna Wolves Legion in bringing the world of Darrowmar into Imperial Compliance.
• c. M30 Compliance of Tarsis - This was an Imperial Compliance carried out by the Ultramarines Legion upon the world of Tarsis against unknown assailants. During the assault the Primarch Roboute Guilliman was attacked by a mysterious assailant, but was saved by a a native soldier of this world. In a supreme display of humility, Guilliman bended his knee before the soldier and vowed a warriors oath that should this world ever need aid then the Ultramarines would answer the call. A temple within the capital city of Erebus displayed the Tarsis Frescoe, a mosaic of enormous proportions painted by an unknown artist that covered the walls, ceiling and even the floor, covering the entire chamber like a canvas. This frescoe displayed the events that had occurred during the Great Crusade. In gratitude to Guilliman and the Ultramarines, the planet renamed itself Tarsis Ultra in honour of its saviours.
• c. M30 Kamenka Troika - This was a campaign of extermination waged in the middle years of the Great Crusade against the barbaric Greenskins (Orks) of the Kamenka Troika. The Emperor had issued the writs of war, commanding the Thousand Sons, the Legio Astorum Titan Legion and a Lifehost of PanPac Eugenians of the Imperial Army to drive that savage race of xenos from the three satellite planets of Kamenka Ulizarna, a world claimed by the Adeptus Mechanicus of Mars. The savagery of that war, the slaughter and relentless, grinding attrition had left tens of thousands of dead in its wake. The Imperial forces proved victorious after two standard years of fighting and earned a score of honours for their war banners. Victory had been won, but the cost had been high. The Thousand Sons sustained severe losses of 873 Battle-Brothers of the 5th Fellowship, effectively wiping the 5th out as a functioning unit. This forced Magnus the Red to reduce his Legion from ten Fellowships to the Pesedjet, the nine classic Fellowships of Prosperine antiquity.
• c. M30 Shi'Hu'Gal Purge – The Night Lords, supported by the Titan Legions Legio Vulcanum I (Dark Fire) and Legio Vulcanum II, carried out the infamous xenocidal purge of the Shi'Hu'Gal Dominion during the Great Crusade; this was a campaign of such fury and viciousness it remains a legend of this bygone era, even after the far greater death and destruction caused by Horus' betrayal of the Emperor.
• c. M30 Compliance of Tethonus - The Luna Wolves fought against an unidentified xenos-adversary whose identity is not recorded in existing Imperial records while bringing the world of Tethonus into Imperial Compliance. This Compliance action was a long siege of the xenos fortress-states on Tethonus. Horus had tasked the masters of the Forge World of Diamat to create continental siege machines; vast artillery pieces that could devastate the most powerful fortifications. But the war machines took much longer for the forge masters to complete than planned. By the time they were finished, the campaign on Tehonus had been over for over a standard year and a half, and Horus had moved on to other conquests. So the weapons were put into a depot on Diamat against the day when he would come to claim them. Fifty standard years later, Horus would reveal his perfidy at Istvaan III, and would send raiding forces to claim these siege engines for later use in his attempt to overthrow the Emperor of Mankind.
• c. M30 Assault on Dahinta - On the world of Dahinta, the Luna Wolves fought against a race of self-aware machines called the Overseers, who were led by the artificial intelligence known as the Archdroid. One of the Emperor's longest-standing commands was that no sentient machines could be allowed to exist, for they had nearly caused the extinction of Mankind when they had rebelled against their human overseers during the Dark Age of Technology. Despite heavy casualties amongst, the thinking machines were wiped from the face of Dahinta by the savagery of the Astartes. Only after the campaign had ended was the full truth learned: the Overseers had been created by a vanished offshoot of humanity that had settled Dahinta, perhaps during the Age of Technology. The Overseers had cared for their lost masters' crumbling cities long after they had become extinct or left their homeworld behind.
• c. M30 Battle of Gyros-Thravian - The Battle of Gyros-Thravian was a massive joint Imperial Compliance action carried out by three Space Marine Legions, composed of the Luna Wolves, Death Guard and Imperial Fists against the extremely powerful Ork Warboss Gharkul Blackfang, one of the most powerful Ork warlords ever encountered up until that time. Despite the strength arrayed against the vile Greenskin, it was the Imperial forces who were soon on the verge of defeat. It was then that the Emperor Himself, aboard his flagship Bucephelus, came to the aid of His sons. He personally led a force composed of 1,000 Legio Custodes into the heart of the mighty Ork horde. Blackfang was confronted by the Emperor and killed atop his Gargant while the Custodians proceeded to lay waste to the rest of the Greenskin horde. The Custodians accounted for the slaughter of the Orks, slaying over 100,000 of the savage xenos, with the loss of only three Custodians. Following their momentous victory, the Emperor commemorated the Custodians' sacrifice by engraving the names of the three fallen Custodians into his own personal Power Armour.
• c. M30 Compliance of Five-Twenty-Nine - This was an Imperial Compliance action carried out by the Alpha Legion against an adversary of unknown origin upon the world designated Five-Twenty-Nine.
• c. M30 Compliance of the Ferinus Worlds - This was an Imperial Compliance action carried out jointly by the Alpha Legion and an Imperial Army sentry force comprised of the Geno Seven-Sixty Spartocid. The Seven-Sixty were a well-drilled regiment and did not spook easily. They played an instrumental role during the Compliance of the Ferinus Worlds.
• c. M30 Compliance of Thorium Abominiplex – This an Imperial Compliance action that was carried out jointly by both the Alpha Legion and Death Guard Legions against an unrecorded adversary.
• c. M30 - M33 The Age of Trade - During this period the Squats trade with the Orks and the Eldar and also make war upon both species.
• c. 800.M30 The Great Crusade Begins - Primarchs rediscovered and united with the Space Marine Legions created from their genomes. The human-settled galaxy is largely reclaimed by the Expeditionary Fleets of the Imperium of Man. The use of accelerated gene-culturing of gene-seed organs to fill the need for vast numbers of Space Marines leads to the development of genetic flaws in many of the Legions.
• c. 850.M30 - The world of Karis Cephalon is resettled by the Imperium of Man during the Great Crusade.
• c. 900.M30 - A highly decorated Imperial Army officer takes the name "Fatidicus," meaning "prophet," and secretly establishes the Temple of the Saviour Emperor on Terra in violation of the atheitic doctrines of the Imperial Truth. Via the Imperial Army and the Imperial Navy, his teachings will eventually spread across the entire Imperium.
• c. 907.M30 Compliance of Forty-Seven Ten - The world of Forty-Seven Ten, also known as Khur, was brought into Imperial Compliance by the Word Bearers Legion approximately a Terran century before the events of Istvaan III at the outset of the Horus Heresy. The beautiful capital city of Khur known as Monarchia, called the Perfect City by the Word Bearers, was built by the people of Khur at the direction and exhortation of the Word bearers to demonstrate their faith and devotion to the God-Emperor.
• c. 923.M30 Keylek Genocide - Early in the Great Crusade the Luna Wolves fought against the hostile alien reptilian race known as the Keylekid on the world of Keylek, ultimately wiping these reptilian xenos from the face of the galaxy. This was a long, brutal and miserable genocidal campaign that was fought long before Horus was made the Imperial Warmaster. At this time Horus was referred to simply as "The Commander" by the Astartes of his Legion.
• c. 947 Compliance of Davin - The Feral World of Davin, codified as Sixty-Three Eight (63-8), was the eighth world brought into Imperial Compliance by the XVI Legion's 63rd Expeditionary Fleet some 60 standard years before the start of the Horus Heresy. The indigenous feral warriors of this world briefly attempted to resist being conquered by the Imperium, but were forced to surrender as they were overwhelmingly outmatched militarily by the Astartes. The warrior tribes were allowed to remain mostly intact as they had impressed Horus with their courage on the battlefield and their willingness to learn to adapt to Imperial culture. The military campaign was brief, and the Luna Wolves departed after the surrender of the Davinites, taking with them their concept of the warrior-lodge, which were quickly adopted throughout the Luna Wolves fleet
• c. 957.M30 Istvaan III Compliance - The world of Istvaan III was brought into Imperial Compliance by the 27th Expeditionary Fleet led by the Primarch Corax. The military forces of the indigenous Istvaanians were professional soldiers who did not break easily, even when confronted with the might of Space Marines. There was some resistance, but the last elements of the aggressive faction were destroyed by the Raven Guard at the Redarth Valley on Istvaan III. An Istvaanian delegation formally surrendered before the Primarch Corax and the 800 companies of Raven Guard Space Marines that comprised his XIX Legion. They kneeled as a defeated foe but were welcomed into the fold as men of the Imperium. Though they had waged war against one another, the Imperial Truth had prevailed and the Istvaanians had sworn to accept its teachings. By proving themselves men of wisdom and civilisation, they were deemed fitting partners for the many other worlds of the nascent Imperium. The Remembrancer Order had not yet been foisted upon the Space Marine Legions by the Council of Terra at this time, but a substantial civilian contingent was left behind to begin the integration of the Istvaanian population with the Imperial Truth. Vardus Praal was left behind as the world's Imperial Planetary Governor to command Istvaan III in the name of the Imperium, to ensure continued compliance and manage the dismantling of the traditional religious structures that defined the planet's autochthonous society. Unbeknownst to Corax and his Raven Guard, they would return fifteen standard years later to the Istvaan System, to the world of Istvaan V, to bring the rebel Horus to account.
• c. 964.M30 Castigation of Khur - Nearly six decades after being brought into Imperial Compliance and some forty-three standard years before the start of the Horus Heresy, the XIII Legion, the Ultramarines, utterly destroyed the city of Monarchia on the world of Khur on the order of the Emperor as an example to both Primarch Lorgar and his Word Bearers Legion that violations of the Imperial Truth through the encouragement of the continued error of religious faith and the spread of idolatrous doctrine would not be tolerated. This action, against a monument to the worship of the God-Emperor they had called "the Perfect City", crushed the morale of Lorgar and his Space Marines and led them to seek out new gods more worthy of their worship -- the Ruinous Powers of Chaos.
• c. 967.M30 Purge of Forty-Seven Sixteen - Forty-Seven Sixteen was the first world brought into Imperial Compliance after the rebuke of the Word Bearers by the Emperor on the world of Khur. It was soon discovered that these people worshipped the Emperor as a God, and that they wanted to join the Imperium. The Primarch dismissed the fact that the people of this world worshiped the Emperor as a God and that they had somehow obtained a copy of the Lectitio Divinitatus scribed by Lorgar himself. The people of Forty-Seven Sixteen were condemned, for ignorance was no excuse for violations of the Imperial Truth.
• c. 967.M30 Pilgrimage of Lorgar - The Pilgrimage of Lorgar was the spiritual quest undertaken by the Primarch Lorgar of the Word Bearers Space Marine Legion during the Great Crusade. Its object was to discover whether humanity's ancient collective beliefs in supernatural entities were true or whether his father the Emperor of Mankind's atheistic, rationalist Imperial Truth was the correct philosophy to guide Mankind's future. In the course of his Pilgrimage, Lorgar learned that the Emperor had lied and that supernatural entities, the Chaos Gods, did exist. Since they were the only deities seemingly in existence, Lorgar believed that they were worthy of humanity's worship. Lorgar would spend the next 40 standard years seeking to turn his fellow Primarchs to the service of Chaos and was ultimately responsible for setting in motion the events that brought on the cataclysmic Horus Heresy.

SourcesEdit

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