The Chalnath Expanse Campaign, also called War Zone Chalnath, was a multisided war fought in the Era Indomitus for control of the Chalnath Expanse region in the northern Segmentum Ultima portion of the Imperium Nihilus between the forces of the Imperium, the T'au Empire's Fifth Sphere Expansion, various Genestealer Cults and the Orks. The campaign has degenerated into a four-way battle that is ongoing with no end in sight.
History[]
Arrival of the T'au[]
The T'au Empire's Fourth Sphere Expansion unexpectedly emerged into realspace after the disastrous activation of their fleet's anti-matter-powered AL-38 Slipstream Modules created the Warp vortex known as the Startide Nexus, a stable, interdimensional pathway or "wormhole" between the region of the northern Segmentum Ultima the T'au named the Nem'yar Atoll and the primary territories of the T'au Empire to the galactic south in the Eastern Fringe near the Damocles Gulf.
Once the T'au Empire confirmed the survival of the Fourth Sphere Expansion's fleet, Commander Shadowsun was given command of the Fifth Sphere Expansion and led it into the Startide Nexus. Once the Fifth Sphere Expansion fleet emerged into the Nem'yar Atoll, Shadowsun integrated the survivors of the Fourth Sphere Expansion fleet into her command and began expanding the size of the T'au Empire's new domain.
Since its discovery by the T'au, the Nem'yar Atoll has become a cluster of Sept Worlds, stellar fortresses and orbital habitation spheres and cities that surround the Startide Nexus, but is also under almost-constant assault from raiders, hostile xenos and other, darker threats such as the forces of Chaos. As such, the military resources allocated to the defence of this key region by the T'au are now considerable, and ultimately led to conflict with the many Imperial worlds located in the same region, which the servants of the Emperor named the Chalnath Expanse.
Commander Shadowsun soon attacked the Cardinal World of Astorgius while the Ctesiphus and Arrajian Systems were the site of major Genestealer Cult uprisings. On the Mining World of Haephos, the Imperial defenders engaged in a bitter guerrilla war against the Genestealer cultists and T'au infiltrators. The Riatov System became a cauldron of constant war between the T'au forces, the Astra Militarum, and the Genestealer Cultists.
The Hive World of Vorotheion seemed immune to the violence for a time before becoming embroiled in a T'au invasion. The T'au wooed disenfranchised and discontented Human populations to the Greater Good, establishing insurrectionist cells and proxies to battle the Imperials alongside their conventional forces. The effects of the Psychic Awakening soon made themselves known on the Humans, with Ecclesiarchy priests performing "miracles" and even Gue'vesa being struck by bouts of emergent psyker-induced insanity.
The disturbances on these worlds caused the Adepta Sororitas' Order Militant, the Order of the Sacred Rose, to respond, saving those who remained true to the Emperor while purging all Heretics and xenos they encountered. Warriors of the T'au Fire Caste put up formidable resistance, but the battle-sisters discovered that the greatest threat to the Emperor's rule in the region were the Ethereals accompanying the T'au forces, whose propaganda concerning the Greater Good was able to claim countless Human souls to their cause.
Imperial Investigation[]
For the servants of the Emperor, each new contact with beleaguered regions in the Imperium Nihilus brought fresh news of falling or fallen worlds, continuing to far outweigh any tales of heroic resistance. In the blighted Chalnath Expanse of the northern Ultima Segmentum, scores of Imperial star systems were in the throes of uprisings and civil wars, scourged by fear-mongering prophets. Into these fractures, more than one xenos ideology seeped. Since the emergence of the Cicatrix Maledictum, the nearby watch fortress of Mortguard and its surrounding watch stations had weathered not only the ferocious Warp storms that had afflicted the surrounding sectors, but surges of xenos as well. Though many aliens had been wiped out by the birth of the Great Rift, many more were driven to invading new territories after losing their own, or were scattered into the path of weakened Human worlds by raging empyric tempests. Such threatening occurrences seemed to have afflicted the Chalnath Expanse.
From its own network of astroduct splicing, comm shunts and informants, Mortguard identified a growing alien influence on the Imperial systems of the Chalnath Expanse. Its exact nature was revealed by Inquisitor Jazad D'ontor. The elderly Ordo Xenos investigator sent an encrypted missive to Mortguard's watch commander, Agathon. The Inquisitor's transcripts and vid-captures showed the hand of the T'au Empire at work. After worming their way onto poverty-stricken Frontier Worlds, the T'au had openly moved against several recalcitrant systems. On some worlds, D'ontor revealed, Astra Militarum regiments attempted to hold back T'au offensives, but other regiments were embroiled in vast civil uprisings of unknown origin. D'ontor had no answers as to how or why the T'au had appeared so far to the galactic north of their primary territory in the Eastern Fringe, but made clear that this was surely only a prelude to a full-scale invasion.
The old investigator had intercepted T'au delegations making for the pivotal expanse worlds of Cestis and Saint's Halt. He had lost a sizable party of Inquisitorial Acolytes in the Arrajian System, too, and believed that all three locations faced being lost. Should they fall, the T'au would spread like a stain, corrupting the Chalnath Expanse from the inside out to threaten the vulnerable worlds at the southern rim of the region. From there, a major Warp route led directly to the Segmentum Fortress at Kar Duniash. The xenos could not be allowed to threaten so vital an Imperial stronghold.
In response, Watch Master Agathon led three entire Watch Companies from Mortguard to the worlds of the Chalnath Expanse. D'ontor's evidence gave suggestions of possible T'au disposition, but the Deathwatch had deeper suspicions. The T'au, they believed, were not the only aliens in the expanse. Broken reports of mutants and religious sects, not to mention D'ontor's missing retinues, all reeked to Agathon of Genestealer Cult infections -- a foe the Deathwatch of Mortguard had fought before.
Assault on Arrajian IV[]
After losing assets sent to scour the trade guilds of the Arrajian System, Inquisitor D'ontor had set watchers at the system's perimeter, sure that a T'au fleet was poised to attack. The Deathwatch, however, believed the canker of a Genestealer Cult was already there. Shrouded rapid strike vessels from Mortguard stalked the system, monitoring vox-traffic and analysing astropathic signals sent to other systems in the Chalnath Expanse.
The Deathwatch discovered that the entire system was on a war footing. The trade guilds were pouring funds into raising Astra Militarum defence regiments as well as private paramilitaries, from the glacial algae seas on Arrajian II to the mag-trawlers skimming the atmosphere of the gas giant Arrajian IX. Everything pointed to preparation for a system-wide conflict, a laudable precaution given T'au aggression against other systems of the expanse.
With a precise teleport strike, a single Proteus Kill-team led by Watch Lieutenant Alvor manifested in the servo-ducts beneath the guildhouse on Arrajian IV. Their aim was to uncover the true reason for the Inquisitor's missing assets. Within solar minutes of their arrival, the kill-team came under attack from "work gangs" of Genestealer hybrids and degenerate Aberrants. Kill-team Alvor pushed through one duct after another, seeking some source to the infection.
For two solar days, the kill-team fought higher into the guildhouse's foundation, losing more and more of their number. All the while their signals back to orbit were blocked by psychosqualls of xenos static. By the third solar day, the kill-team had slain dozens of xenos-corrupted guilders, but only Brother Tyvus survived to pull himself to the surface and activate his teleport homer, taking into orbit a tale of widespread alien infection and twisted experimentation.
Within solar months the system had fallen to the Genestealer Cult, but Mortguard now knew the truth and would return.
Battle of Cestis[]
On the mountainous and barren world of Cestis, in the south-east quadrant of the Chalnath Expanse, T'au pioneers of the Fifth Sphere Expansion had already gained a foothold. Their Earth Caste engineers had erected a research station, while their Water Caste envoys bribed Human black marketeers to keep its presence hidden. Watch Captain Seraphus, who had overseen the interrogation of one such pirate, knew from his Ordo Xenos data-inloads that these sites were the T'au's common means of eventual invasion. Either built piecemeal inside such stations by a veritable army of the aliens' robotic drones, or snuck in under a stealth field projected by its domed surface, these structures could amass huge military presences under a charade of "scientific research."
Attacking with all haste, the Deathwatch deployed air superiority squadrons and heavy ground forces supported by Land Raider armoured transports. The tanks advanced through valley floors, converging along routes established by a preceding Spectrus Kill-team. Drone-controlled turrets bearing T'au heavy weaponry studded the valley walls firing towards the Imperial force as swarms of drones poured from hidden boreholes. The Deathwatch's snipers felled dozens of the skimming drones, while heavier fire carved into the turrets that lined the scree.
Portals opened in the research station's curved surfaces and T'au Battlesuits jetted out. Their weapons immobilised one Land Raider, blocking the route for those behind. In response, Deathwatch armoured battle groups joined sniper fire squads and set up lethal kill zones.
What should have been a single hammer blow would drag on in a battle of attrition, spreading across the mountains of Cestis as both sides continued to pour larger forces into it.
Battle of Saint's Halt[]
The Chalnath Expanse Shrine World of Saint's Halt was home to billions of people. They crowded into cramped coastal cities that were squeezed between acidic seas and inland plateaux dominated by continental reliquary palaces. The Deathwatch strike cruiser Void Sentinel, upon translation into the system, found the world already under siege by the forces of the T'au Empire. Native Planetary Defence Force infantry regiments of the Saint's Tidecasters fought alongside the battle-sisters of the Order of the Blue Robe, and Astra Militarum forces from the Riatov and Pennutsk Systems that had breached the T'au orbital blockade to reach the surface.
From Void Sentinel's command throne, Watch Master Agathon conducted Mortguard's global campaign against both T'au cadres and Genestealer Cult uprisings. Hive Tor Saev burned, illuminating the southern pole. At Hive Delina, the Absolutis Arch was hung with bloody Loyalist corpses as their Genestealer Cultist murderers defended the city from T'au bombardment. Vast battle lines had opened up around every major hive city; Agathon concentrated his strikes against three.
At Leonis Hive, the watch master directed kill-teams to sabotage a Shield Generator protecting the T'au flank from Riatov artillery companies. To Gedronis, he dispatched waves of Storm Speeders to cut off the xenos grav-tanks attacking the Gate of the Emperor's Vengeance, hoping to allow the Adepta Sororitas trapped there to break out. Mortguard's Watch Company Quintus in its entirety smashed into the T'au offensive outside the planetary capital city, Boran Prime. In a storm of special-issue bolter ammunition, cleaving blades and psychic scourges, the T'au buckled. The Deathwatch drove them back into the claws of xenophile cultists who declared themselves to be the Hivewyrm, forcing the two breeds of xenos to turn on each other.
In orbit, Deathwatch reserves awaited the ambushes Agathon knew both faithless xenos species were capable of initiating. When the next one struck, he would be ready, as the war for the Chalnath Expanse ground on.
Ork Invasion[]
Drawn by the raging, three-sided conflict in the Chalnath Expanse, massive Ork forces soon arrived in the region. They poured from the Ful'na Nebulae in ragtag invasion fleets. With the Thaxaril, Riatov, and Barolyr Systems barely pacified, the conflict continued to rage on half a dozen other fronts.
Commander Shadowsun proved unwilling to allow this new menace to destabilise the precarious expansion of the Nem'yar Atoll into Imperial space. Deploying her forces in a complex web of interlocking positions throughout the Vy'las, Mets'ah, and Aso'da Systems, she began a Kauyon-style campaign on an interstellar scale. She planned to use this strategy to blunt the Greenskins' momentum and crush the threat they posed to the continuance of the Fifth Sphere Expansion.
Sources[]
- Codex: T'au Empire (8th Edition), pp. 22-24, 27
- Codex: T'au Empire (9th Edition), pg. 24
- Codex Supplement: Deathwatch (9th Edition), pp. 18-19
- Psychic Awakening: The Greater Good (8th Edition), pg. 6