The Avernian Imperial Guard —commonly referred to as the Hellwatch or simply the Watch—are the primary Imperial military within the Umbral Sector. Renowned for their expertise in combating the forces of Chaos and the warp, the Avernian Guard are specialists in rapid mechanized warfare, their soldiers exhibiting a rare, innate resistance to the corrupting influence of the Immaterium.

This natural resilience, coupled with their battlefield effectiveness, has made Avernian Dragoon regiments highly sought after by both Inquisitorial agents and Astra Militarum commanders engaged in campaigns against the Ruinous Powers.

However, such traits have also drawn suspicion. The Avernians’ unorthodox combat doctrines—developed over two centuries of isolation from the wider Imperium—are viewed by some as dangerously divergent. Their genetic fortitude against psychic heresy is marked by a visible and often maligned sign of their divergence from baseline humanity: amber-hued eyes with shifting, lambent irises.

Homeworld

See more: Avernus

Avernus is a heavily-fortified Death World that serves as the capital of the Illryian Protectorate, a semi-autonomous region that serves as the Imperial remnant within the Umbral Sector. Though not as historically industrialized or densely populated when compared to other worlds in its class, Avernus holds strategic and esoteric significance due to its unique metaphysical properties. The veil between the material realm and the Immaterium is unnaturally thin across Avernus, resulting in frequent warp phenomena and psychic disturbances.

Over millennia the human population of Avernus has undergone subtle but profound genetic drift. Exposure to the warp’s ambient energies has led to the emergence of a rare trait: a natural resistance to the corrupting influence of Chaos and the psychic predations of the warp marked by yellow irises. While not entirely immune, Avernians exhibit an instinctive resilience that makes them highly valued as servants of the Inquisition and the orders militant of the Astra Telepathica. Soldiers in the Avernian Guard are similarly valued and Avernian regiments are often drawn for deployment into warp-ridden environments deemed inhospitable for human life.

Avernus’s landscape is lush and pastoral. Most of the planet’s population and manufactora are hidden behind the walls of bastions, fortress cities ruled by the dynasties of the royal houses. In the vast alpine wilderness between bastions lie dangerous realms known as nethers where the veil is particularly thin. Here the Immaterium bleeds into the material realm and marks the landscape with unnatural characteristics such as crystalline mountain ranges, shimmering auroras, and the ruins of lost cities where time behaves erratically. Dangerous to even the warp-hardened Avernians, the nethers are host to aurumite – exceptionally valuable and warp resonant ore used famously in the armor of the Adeptus Custodes.

Imperial authorities maintain a cautious presence on the world. Scholastica Psykana enclaves and Black Ship waystations are established on and near Avernus to monitor and harvest the planet’s unique human stock. Servants of the Adeptus Custodes also keep watch over the world, and agents of the the Eyes of the Emperor occupy key economic and political positions within the Avernian government to ensure the continued supply of aurumite to Terra.

The Inquisition also hosts a permanent presence on Avernus. Within the largest nether on the planet, they maintain a heavily-fortified headquarters known as the Black Citadel. The Black Citadel hosts a Schola Progenium academy to train acolytes and inquisitorial stormtroopers for operations in warp-corrupted environments. But within its cavernous depths (and far from the prying eyes of its orthodoxy) the Black Citadel is rumored to host labs dedicated to experimenting with dangerous Dark Age and xenos technology.

Despite its dangers, Avernus remains a vital asset in the Imperium’s eternal war against the forces of the warp.

Regimental History

The Avernian Guard trace their origins to The Fall, an era beginning at the end of M.40 when the Umbral Subsector was cut off from the wider Imperium by warp storms and the collapse of stable astropathic routes. Isolated for over two centuries, the planetary defense forces of Avernus evolved into a self-reliant, highly adaptive military force. During this time, the Guard developed unique doctrines and technologies suited to the warp-tainted conditions of their homeworld and surrounding systems.

Following the reestablishment of contact with the Imperium during the Era Indomitus, the Avernian Guard were formally inducted into the Astra Militarum. Their proven record against daemonic incursions and warp anomalies earned them the moniker Hellwatch, a title both feared and respected across the Imperium.

Doctrine and Organization

Combat Doctrine

Avernian military doctrine emphasizes speed, precision, and psychological resilience. Regiments are structured around highly mobile mechanized infantry supported by fast-attack armor with integrated psyker suppression units. Combat formations are trained to operate independently for extended periods, a legacy of their centuries of isolation.

Unlike standard Astra Militarum forces, Avernian command structures allow for greater tactical autonomy at the company and platoon levels. Officers are selected not only for strategic acumen but for their resistance to warp influence, often undergoing rigorous psychic screening and exposure trials before promotion.

Specialized Units and Equipment

The Avernian Guard field several unique formations, including:

Slayer Commandos

Inquisitorial stormtroopers trained from infancy at the Black Citadel to support the operations of the ordos. Also known simply as Commandos, they’re trained to operate from low orbit and infiltrate via high altitude gravchute insertion. Avernian Guard regiments are often accompanied by a battalion of commandos that serve as the force’s reconnaissance, rapid reaction, and special operations personnel. Due to their indoctrination and training within the Ordo Prefectus they also serve as feared enforcers for regimental commissars.

Royal Guard

Elite heavy infantry that serve as the vanguard for most Watch infantry detachments. Trained by the Royal Houses to defend their strongholds and dynastic lines, the Royal Guard are equipped with the finest equipment the Watch have to offer: carapace armor, hellguns, and modified Taurox and Chimera variants equipped with warp-dampening field projectors and enhanced auspex arrays. While most Royal Guard are recruited from veterans of offworld campaigns, some houses have programs similar to those at the Black Citadel that train adepts from a young age. Young Acolyte Scouts who have come into the Royal Guard through this pathway are often attached to regiments to gain battlefield experience, and provide forward reconnaissance for infantry and mechanized battalions.

Nullborn Auxilia

Ogryn who survive a torturous process at the Black Citadel known as “Rebirth” to become psychic blanks. While typically only occupying the Phi-plus levels of psychic resonance, the presence of a Nullborn Auxilia is more than enough to disrupt rogue psyker or daemonic activity (as well as unnerve non-Avernian humans unaccustomed physically or psychically to their presence). They usually serve as bodyguards to strategic personnel or as expendable shock troops sent to pacify daemonic or sorcerous threats.

Hellriders

Mounted infantry trained to operate and perform reconaissance within the nether. Because complex equipment and machine spirits can fail in the reality-bending depths of the nether, Hellriders are mounted on horseback and experts with their simple but devastatingly effective melee weapons.

Equipment

Avernian standard-issue equipment is often retrofitted with anti-warp sigils, psychic shielding, and auramite-infused alloys mined from Avernus’s crystalline sublayers. These are common and necessary for domestic forces operating within the nether, but are esoteric and rare equipment offworld. Examples of this include the hermetically-sealed Illryian “Aegis” Pattern Hazard Suits and their variety of variants worn in battle by Hellwatch.

Avernian las weapons typically consume higher amounts of power than their Militarum counterparts and typically have a far smaller ammo capacity (e.g.: 30 rounds compared to the 60+ rounds per standard magazine) and a slower rate of automatic fire than other variants. However they are often hit harder, are more rugged, and are far more reliable in the warp-corrupted environment the Watch operate within. Anecdotally they are also marginally more effective against daemonic and psyker threats.

As such, Avernian las weapons are highly prized by the Inquisition and wealthy militant forces likely to encounter such adversaries such as the Black Sentinels of the Astra Telepathica. Examples of these include the family of Type 39 Avernian las rifles standard issue to most Avernian Guard forces, and the Avernian M-41 variants of hellguns.

Order of Battle

A standard Avernian Guard regiment is a highly mobile, warp-hardened fighting force composed of multiple specialized battalions, each designed to operate autonomously or in concert during extended campaigns in warp-tainted or high-threat environments. The regiment is structured to maximize flexibility, rapid deployment, and resilience against both conventional and daemonic/psyker threats.

Typical Regimental Composition:

• 1st Dragoon Battalion
  Spearhead battalion equipped with Taurox and Chimera transports and warp-shielded support vehicles. Trained for rapid assaults, urban warfare, and to establish beachheads for future operations.
• 2nd Mechanized Infantry Battalion
  Functions as a reserve and reinforcement element, often deployed to secure flanks, supply lines, or reinforce breach points.
• 3rd Armored Support Battalion
  Fields Leman Russ variants, Hellhounds, and Rogal Dorn heavy tanks. Provides cavalry armored strike forces, siege-breaking capability, and supplies dragoon strike forces with heavy armor support.
• 4th Reconnaissance and Surveillance Battalion
  Operates sentinels and scout vehicles equipped with warp-anomaly detection systems. Responsible for forward observation and early warning.
• 5th Commando Battalion
  An elite formation composed of warp-adapted infiltration specialists. Commandos are deployed for deep-strike operations, daemon-hunting, and sabotage missions behind enemy lines. Equipped with grav-chutes, hellgun carbines, and auramite-bladed melee weapons, they are feared for their precision and psychological warfare tactics.
• Psykana Liaison Detachment
  Attached to each battalion’s headquarters company, this unit includes sanctioned psykers, null-adepts, and astropathic relays. They serve as both battlefield assets and warp-monitoring agents.
• Regimental Command Company
  Led by a Lord Marshall, supported by a senior staff of tacticians, logisticians, and often a representative of the Inquisition when deployed on Ordos business. Oversees strategic coordination and liaison with Imperial command structures.
• Logistics and Engineering Corps
  Maintains supply chains, vehicle repair, and fortification construction. Trained to operate independently in hostile or warp-unstable environments.

Each regiment is designed to function as a self-contained strike force, capable of prolonged deployment in warp-affected warzones without immediate resupply or reinforcement. The inclusion of the Witchslayer Commandos ensures that even the most insidious threats can be met with surgical precision and overwhelming force.

Notable Campaigns

The Millennial War (M40.999)

In the immediate aftermath of the Great Rift’s violent birth, the Umbral Sector was plunged into chaos. Warp storms severed astropathic communication, daemonic incursions erupted across dozens of systems, and traitor legions surged from the shadows. Among the most devastating assaults was the invasion of Avernus itself—homeworld of the Hellwatch.

The attackers were led by the Volscani Cataphracts, a brutal and fanatical traitor host whose betrayal led to the fall of Cadia. Allied with renegade psykers, separatist PDF regiments from other worlds within the Umbral Sector, and daemonic entities drawn to Avernus’s thin veil to the warp, the Cataphracts launched a full-scale planetary invasion. Their goal: claim the world as a warp-blighted shrine to Chaos Undivided and annihilate the last Imperial resistance within the sector.

The Avernian populace and PDF, supported by the entirety of the Slayer Commando corps, mounted a desperate defense. Fighting across the bastions of Nachtgrad, High Orison, and the sacred crystal fields of the Auric Vale, the Avernians employed scorched-earth tactics, psychic nullification zones, and rapid mechanized counteroffensives to stall the enemy advance.

Under direct orders from the Ordo Malleus, the Hellwatch enacted Protocol Obsidian, a classified contingency plan. This included the evacuation of key psykana personnel, the destruction of warp-sensitive relics, and the activation of the Sentinel Towers —ancient planetary defense grids hidden beneath Avernus’s crust since the Age of Strife.

Despite being outnumbered and surrounded, the Avernians held the line for oover a century. The Slayer Commandos, operating behind enemy lines, assassinated traitor warlords, sabotaged supply lines, and detonated auramite charges within warp rift nexuses, delaying the daemonic tide.

Ultimately, the arrival of a Grey Knights strike cruiser and a Mechanicus Ark Mechanicus broke the siege, purging the Cataphracts with orbital bombardment and psychic cleansing. Avernus was saved—but at a terrible cost. Over a third of the planet’s surface were rendered into uninhabitable nethers, and over ten million Avernian soldiers and civilians perished in what would later be known as The Great Sacrifice.

The defense of Avernus became a rallying cry across the Umbral Sector. The Hellwatch had not only preserved their homeworld but had proven that even in the darkest hour, humanity could defy the abyss. And from this pyrrhic victory, the Avernian Imperial Guard were born.

The Purging of Caerost Hal (M41.812)

In the wake of a catastrophic warp breach on the agri-world of Caerost Hal, daemonic entities poured through rift nexuses, overwhelming the planet’s primary settlements and reducing its once-fertile plains to scorched, warp-tainted wastelands. The 47th Avernian Dragoon Regiment was deployed under the authority of the Ordo Malleus to contain the incursion and prevent the corruption from spreading to neighboring systems.

Operating under extreme atmospheric instability and psychic interference, the Witchslayer Commandos conducted a series of precision strikes against the warp rift nexuses. Utilizing auramite charges and null-field generators, they successfully collapsed the breaches and severed the daemonic foothold before it could metastasize.

The campaign was concluded in under three standard weeks, with minimal civilian casualties—a feat attributed to the Avernians’ innate resistance to warp corruption and their seamless coordination with Inquisitorial strike teams. Caerost Hal was later declared sanctified and remains under long-term surveillance by the Ordo Malleus.

Operation Silent Pyre – The Varl Prime Incursion (M42.104)

A covert campaign executed in the shadow of the Gates of Varl, Operation Silent Pyre remains one of the most heavily redacted missions in the annals of the Avernian Guard. Declassified fragments confirm the deployment of the 19th Avernian under the direct command of Inquisitor-Lord Kael Varn of the Ordo Xenos to the quarantined Forge World of Varl Prime—a world long sealed by Imperial decree due to its proximity to the warp-scarred region known as the Gates.

The mission was triggered by a surge of psychic static and gravitational anomalies emanating from the ruins of The Annihilator, a xeno-archaic structure once constructed by Archmagos Bastian Ghuul under the influence of the entity known only as the Beast of Fear. Intelligence gathered from the interrogation of Tech-Adept Uvochi and the aftermath of the Ordex-Thaag detonation suggested that a surviving sect of the Teeth of the Cog had returned to Varl Prime, attempting to reactivate the Annihilator using a second Varlian Device—a relic capable of severing the veil between realspace and the warp.

The Slayer Commandos were inserted via grav-chute into the irradiated ruins of the Forge World, where they engaged in a prolonged shadow war against corrupted Skitarii, rogue psykers, and warp-possessed constructs. Temporal instability plagued the operation—squads reported time dilation, memory loss, and encounters with entities that defied classification.

Despite these conditions, the commandos succeeded in infiltrating the Annihilator’s core and neutralizing the Varlian Device moments before activation. The cost was severe: all non-Avernian support personnel were lost, and over half the Witchslayer battalion was declared missing in action, presumed consumed by the warp.

The operation concluded with the detonation of auramite charges, collapsing the Annihilator’s central spire and sealing the breach. Varl Prime remains under permanent quarantine, its skies patrolled by Mechanicus null-satellites. The Avernian Guard were awarded the Inquisitorial Sigil of Silence, a rare commendation granted only to those who have served in operations deemed too dangerous to ever be spoken of again.

Operation Ashen Mantle – The Fall of Sanctus Terra (M42.112)

During the final stages of the Nachmund Gauntlet Campaign, as the Imperium initiated a strategic withdrawal from the region, the fortress-world of Sanctus Terra—a key Inquisitorial stronghold and relic repository—came under imminent threat from advancing Chaos forces. The 88th Avernian Dragoon Regiment, under direct orders from the Ordo Malleus, was deployed in a classified operation codenamed “Ashen Mantle.”

The mission objectives were clear and uncompromising:

• Evacuate all Inquisitorial personnel and high-value assets from Sanctus Terra.
• Secure and extract sacred relics recovered from both Sanctus Terra and Vigilus, many of which were deemed too dangerous to fall into enemy hands.
• Locate and remove a cache of atomic warheads, hidden beneath the planet’s surface for future Exterminatus-level contingencies.

Operating under constant warp interference, the Avernian Guard executed a multi-phase extraction across three hive bastions. The Slayer Commandos spearheaded infiltration into the Vaults of Saint Halbrecht, neutralizing cultist resistance and securing the relics before the vaults were collapsed via controlled demolition.

Simultaneously, mechanized elements of the 1st and 2nd Battalions established a defensive perimeter around the Inquisitorial bastion-fortress of Aegis Sanctum and its nearby aerodrome, holding off waves of traitor Astartes and daemonic entities long enough for evacuation transports to break through traitor lines.

The final phase of the operation saw the Nullborn Auxilia descend into the irradiated catacombs beneath Hive Solace, where they retrieved and disarmed the Inquisition’s atomic arsenal. These weapons were later relocated to a secure vault-world under Ordo Malleus jurisdiction.

Though Sanctus Terra ultimately fell, the success of Operation Ashen Mantle preserved irreplaceable relics, personnel, and strategic assets vital to the Imperium’s continued resistance in the Segmentum Obscurus. The 88th Avernian Regiment was awarded the Sigil Obscura for their actions—an honor rarely bestowed upon non-Astartes forces.