Across a million worlds nestled within the grand tapestry of the cosmos, mankind grips the earth with stubborn tenacity, finding homes in the most palatial spires, and the most unforgiving rocks whistling through the great void. From jungle death world to crowded underhive, from glacial blizzards of razor sharp ice, to the merciless light of binary suns that bleach radioactive deserts, humanity endures. By the will of the God Emperor, and the unflinching spirit common to all of human stock, the species plants its feet astride the interstellar darkness and dares the universe to remove them.

The universe has yet to succeed in that goal, but we would be remiss to say it has not tried its hardest. One corner of our galaxy tells this story well; a tale of both the triumph and folly of mankind, its contradictory propensity for self destruction, and simultaneous will to survive no matter the odds. This place is known as the Gulf of Athena, a broad spread of roughly a thousand stars named by someone both long dead and long forgotten, but whose legacy clearly endures. 

The Gulf of Athena lies in the Ultima Segmentum, and is centered around a malignant warp storm known simply as The Maw. It is also the intersecting point between three major sectors: The Acheron Sector, the Styx Sector and the Orpheus Sector (not to be confused with the Orpheus Sector, Segmentum Obscurus). Classified as a "gulf" due to the relatively sparse clustering of star systems in this region as compared to its relative galactic north and south, it is also a hotly contested area of Imperial space following the events of the Noctis Aeterna and the spread of the Cicatrix Maledictum. 

An overview of the Gulf of Athena Region at the turn of the 3rd Century M.42. with annotations of interest to documented major conflicts currently on record. Subject to further updates. Does not include various sub-sectors - for these see chart 721866GOA22b.

Earliest Known History:

The gulf region is speculated to have been first colonized by mankind sometime during the period between M.16 and M.24. Discoveries by adepts of the Adeptus Mechanicus' Ordo Archaeologica in the region have found ruins confirmed to be human that date back as early as 511.M16 as well as astral debris that possibly dates back even further. 

It is speculated that humanity first arrived in this region at the dawn of what we have come to understand as the Age of Technology, and the Gulf of Athena represents one of the early targets of expansion and colonization by mankind's fledgling domain, displacing a number of alien species in the process, principle among which being the Aeldari, based on the high concentration of pre-fall ruins scattered in the region.

Reunification with the Imperium:

In M.31 the Gulf of Athena was re-conquered and brought to compliance by several expeditionary fleets of the Emperor's Great Crusade. Surviving records make mention of the 211th, 542nd and 215th Expeditionary Fleets led by the VIII Legion (Imperial Fists) as well as auxiliary forces of the 728th Expeditionary Fleet led by the XVII Legion (Word Bearers). It is during this period the modern entity that is the Gulf of Athena takes form. Originally the boundary point between two sectors, Styx and Acheron, the latter was sub-divided and the Orpheus sector was born some time during or after the Scouring.

The Horus Heresy:

During the Horus Heresy the region was the site of fierce conflict between loyalist forces and traitors, predominantly elements of the XVII legion (Word Bearers), who fought a protracted interstellar siege from within their ring of worlds surrounding the Maw. Fragments of information from this period are scarce, as most loyalist forces were eventually pulled out of the region in order to redirect vital assets towards the battle of Beta Garmon, and later the Siege of Terra itself. This left the gulf mostly uncontested and in traitor hands. Of this dark time virtually no record survives. Rumours persist of ancient cults, covens and buried temples constructed by the Word Bearers on a hundred worlds in the gulf before the end of the Heresy. Imperial citizens can rest assured that these are all false, and no evidence pointing to their existence remains.

For most of the conflict, the region was abandoned by the Emperor's forces until the time of the Scouring, at which point the forces of the Word Bearers fortifying the occupied region were slowly pushed back by a crusade armada led by several astartes chapters including the Ultramarines, Imperial Fists, Black Templars and Praetors of Orpheus. Records of this campaign are much easier to find, and detailed accounts may be found elsewhere within this volume concerning events such as the so-called "War for the Hollow World", the Siege of Deathmire, and one of the gulf's largest naval battles on record, known as the Battle of the Delta. After suffering repeated defeats at the hands of the superior Imperial armies, the traitor legionaries began a fighting withdrawal back towards the Maw itself, leaving scorched worlds and entire populations of heretical cultists in their wake. Finally, after the battle of the Cerberus Gauntlet, they retreated into the depths of the warp storm itself, from which they would rarely emerge in force over the course of the following 10,000 years.

Cataphractii-pattern Terminator of the XVII Legion "Dark Maw" Chapter, charged with the defence of the Gulf of Athena by the traitor Primarch Lorgar:

The Age of Apostasy:

After the end of the Nova Terra Interregnum, during which Chaos activity in and around the Maw showed the first signs of increasing since the days of the Great Scouring, three chapters of the Adeptus Astartes were founded and assigned permanent garrison worlds around the Maw. These three chapters were the Revenants, the Stormriders and the Silver Saints, who collectively became known as the Cerberus Warders, a reference to both the three headed dog of ancient terran myth, and the vital strategic location known as the Cerberus Gauntlet, a stable corridor of realspace that leads into the Maw itself.

During the civil wars that we now collectively have come to refer to as the Reign of Blood, the Imperium was thrown into bitter conflict, and the Gulf of Athena was not spared. With local forces weakened by events abroad, the ruinous powers lurking within the Maw stirred, and the following events would prove to be the first great test of the Cerberus Warders.

Tactical Marines from each of the Cerberus Warders chapters. The Silver Saints (pictured left), the Stormriders (pictured center) and the Revenants (pictured right):


It began with dozens of worlds around the Maw falling eerily silent as cults whose seeds had first been planted in the days of the Horus Heresy rose up and overwhelmed their planetary governments with a precision and timing that took even the vigilant astartes completely by surprise. The warders were created solely for the purpose of defending the wider gulf from the cancerous influence of the ruinous powers, but in truth they had never been truly tested until now, and their response was sluggish and un-coordinated. The three chapters were used to generally maintaining a minimum garrison force while their presence was required elsewhere within the sector and beyond, joining crusade armadas, and rallying to defend critical locations from xenos invaders. When the ruinous powers came knocking, the Cerberus Warders' original purpose was fading from memory.

The Stormriders were the first to meet the foe in battle. Of the three chapters, they were based the closest to the heart of the storm (hence their name), manning a series of star forts that stretched across the width of the Cerberus Gauntlet itself. A fleet based chapter, most of their strength was theoretically supposed to be marshalled at this singular choke point, but when the traitor legionaries struck, most of their fleet was elsewhere, deployed in an ongoing crusade against the greenskin hordes of the Arch-Arsonist of Charadon. 

A massive armada of Chaos vessels, led by the Word Bearers Chapter of the Dark Maw emerged from the storm just as news of the cult uprisings was reaching the ears of sector authorities. The Stormriders, undermanned as they were, still managed to hold the Gauntlet for a month before the traitors broke through. The rest of the chapter was immediately recalled, but would not arrive before it was too late. By this time the Revenants and Silver Saints were aware of the attack, and marshalled their own considerable fleets to halt the Chaos advance. The Departmento Munitorum marshalled new regiments of the Imperial Guard at a rapid pace (rapid by munitorum standards, at least), and after a series of minor skirmishes and naval duels, battle was joined in earnest outside the Tombstone Nebula.

Map of the Cerberus Gauntlet as it appeared at the time of the attack. Additional annotations describe when imperial assets were destroyed, starting with Mark 00.00.00, when the Last Vigil was destroyed by internal sabotage.

The day proved eventually to be a victory for the Imperium, though what remained of the Stormriders chapter was destroyed in the process and the survivors also endured very heavy casualties. The damage was done, and all who lived to see the end of it vowed it would never happen again. They were of course, very much mistaken in that assumption.

The Cicatrix Maledictum:

The Fortress that was the Imperium held for another four thousand years. Not an insignificant achievement by any stretch of the imagination, however mounting new threats, such as the Tyranid hive fleets, the waking Necron tomb worlds, and Abaddon the Despoiler's successful marshaling of the forces of Chaos on a concerning scale eventually proved too much.

The fabric of the universe split asunder, the warp boiled into real space. Stars went out, fleets were lost, creatures born of nightmares stepped across the veil into the world of the living. The astronomicon, the guiding light on Terra that shepherds Imperial vessels through the warp, flickered out. This dark time became known as the Noctis Aeterna.

Fully half of the old Imperium was lost, burning and shattered behind the curtain of the galaxy-spanning Great Rift. The other half fared only slightly better. The Gulf of Athena, for its part, burst into flames as xenos invaders, rebellious uprisings and cosmic phenomena ate up entire sub-sectors within the space of weeks. The Maw, swollen like a flooded river, burst its banks.

A map of the imperium following the coming of the Great Rift.

The remaining Cerberus Warders, the Revenants and the Silver Saints worked closely together in the years following the previous war to rebuild a system of star forts and planetary defences that could defend the approaches in and out of the Maw, the largest of which being the Cerberus Gauntlet. Their work was based on lessons learned in the dark days of their previous failures, and they felt confident in their work.

There is an old Terran maxim that generals learn to master the previous war, just in time for the new one. It remains true. For all their planning, all their building and fortifying and training, the great enemy outsmarted them once again. They believed that the treacherous Word Bearers were defeated at the battle of the Tombstone Nebula, but in reality, only a fraction of the traitors' strength had been deployed to the attack which in the end destroyed an entire Space Marine chapter.

The sons of Lorgar were playing the long game. For them, life had been one long siege that began the day their primarch ordered them to secure the Styx sector during the Horus Heresy, 10,000 years ago. They had weathered the Scouring, given up ground, withdrawn to their impregnable keep that was the warp storm, and from time to time, sallied forth to achieve necessary objectives. They had previously succeeded in utterly destroying one of the three chapters of space marines dedicated to defeating them. Two still remained. 

When they attacked this time, it was in full force, and with the immaterium itself as their ally. When the Great Rift tore across the cosmos, the Maw swelled along with it and in a torrent crashed over the carefully laid defences of the Imperium. Star Forts and planets alike were swallowed by the maelstrom, choke points were rendered meaningless, the Imperium's defences were thrown into disarray, and from the depths of this fresh new hell sailed an armada of vessels not seen in ten millennia, led by their ancient flagship - a Gloriana Class Battleship named the Throne of Obsidian.

Hard times followed. In the initial confusion, the Word Bearers were able to carve out a small empire in the Styx sector with very little resistance, and with each fresh conquest, a new planet of mortal converts joined their cause. Day by day, week by week, month by month, their black crusade continued. The Imperium's forces, blinded by the loss of the astronomicon were paralysed to respond in a co-ordinated fashion, but even so, there were some who resisted.

The Revenants and the Saints held their forces close to home after learning the folly of underestimating the traitors in the past, and so when their own systems came under attack, they fought fiercely and in great numbers against the foe. Key to their survival in this contest was the disorganization of an enemy that was both chaotic by nature and bloated on too many easy victories. The traitors were over extended - in ten millennia of creeping madness, the art of managing an empire was a hazy memory to them. Fleets would arrive to the fight in small, disorganized battlegroups led by aspiring champions eager for glory in a battle they mistakenly thought was a guaranteed victory. What they met was two chapters of the Emperor's finest that had dug in, fortified, and marshaled the populace of a whole sub-sector in grim defiance. Every man, woman and child that could bear arms was thrust into the defence, or worked near to death in manufactora to produce ammunition and supplies for the defenders. Both chapters of space marines boosted their recruitment rate of aspirants to the limit of what their facilities and logistics would allow, and by the time the battle began in full, both had exceeded the mandated number of space marines under arms dictated by the codex astartes.

An armoured column of the Revenants Chapter readies itself to move out against traitor forces in the equatorial deserts of Hades.

They fought for years in the dark with their backs to the wall against a foe older and mightier than themselves, and defied them. They truly believed the Imperium was doomed, it was agreed among the joint high command that the loss of the astronomicon could only mean that Terra had fallen. Indeed, some of the last communications received from the wider Imperium before night fell had described the fall of Cadia. It was their assumption that the Despoiler had marched on the Sol System and finally succeeded where his father, Horus, had not. In spite of this however, they still exhibited that uniquely human fury of resistance, that grim determination not to go quietly into the night, and little did they know, their sacrifice would be rewarded.

It is said that when the light of the astronomicon returned, the morning sun was cresting on the horizon as the imperial defenders mustered on the walls of the Revenants' polar fortress on Hades. Chapter Master Cyrus voxed a single phrase, prepared in advance, that let all loyalist forces on the battlefield know that the Emperor's light burned across the heavens once more: "Dawn breaks on Holy Terra."

The fight was not entirely over, but within a month, Imperial vessels bearing designations tying them to Roboute Guilliman's Indomitus Crusade arrived at the system's mandeville point, and the Word Bearers finally retreated.

The Acheron Crusade:

The defenders of the Styx sector were incredibly lucky. This much is obvious. While they had survived thanks to reinforcements in the nick of time, there were thousands of other valiant defenders of the Imperium that fought to the last, waiting for help that never came. The Gulf of Athena itself was still in flames. While the traitors had been halted in their advance temporarily, they had still come to occupy a vast stretch of space that would take centuries to shift them from. To the galactic west, the Acheron sector had fallen into complete anarchy and disarray with aliens and renegades running rampant over a once prosperous domain. 

An effort had to be made to take back the gulf from the clutches of mankind's many enemies, and a vast crusade armada was assembled. Pale in comparison to the primarch Guilliman's mighty Indomitus Crusade, it was nevertheless the largest concentration of the imperium's might the region had seen since the days of the Scouring. The Revenants and Silver Saints, with primaris reinforcements led the tip of the spear, joined by a shield company of the Adeptus Custodes, agents of the Emperor's Inquisition, Skitarii and Titan legions of the Adeptus Mechanicus, and a number of households of Imperial Knights. Last, but definitely not least came the soldiers of the inexhaustible Astra Militarum, including both local regiments and veterans from the battles for Cadia and Mordian. This vast convocation of imperial might had one goal: Push west, retake the Gulf of Athena, and suffer not the heretic, the mutant nor the alien to stand in their way. It was named the Acheron Crusade, and for the last 150 years, their war of furious reconquest has raged across the Gulf of Athena. Many stories of the heroes of this mighty force have already been told, while some have yet to ascend to greatness. Rest assured dear reader, that all of them will find their way into this humble archive.

Two soldiers of the Cadian 404th Mechanized Infantry Regiment pose for a pictograph on the fields of Athkatlos II