Steel Sentinels

"They think themselves strong...but we are beyond strength."

- Chapter Master Mahar, of the Steel Sentinels

The Steel Sentinels are a Space Marine Chapter of unknown gene seed stock, though their tactics lend themselves to siege warfare, drawing much of their combat doctrines and strategies from the writings of Rogal Dorn and Rouboute Guilliman. They are a fleet based chapter operating primarily on the borders of Segmentum Ultima.

Founding
The Steel Sentinels claim to have been founded by a decree by the High Lords to watch over the Wreath Sub-Sector, a region plagued by regular Ork invasions, renegade activity and xenos plots. Historically the region has been defended by the local Astra Militarum and Segmentum Fleets assigned to the area, occasional intervention by the Steel Sentinels having been documented throughout the millennia.

Dispersal
According to Chapter records, the Steel Sentinels' fleet was split up soon after it reached full strength, reinforcing a number of key strategic points, raiding renegade worlds, destroying defences, liberating the enslaved populations then departing once the Astra Militarum arrive to occupy the planet. Some fleets struck out at xenos held space, spending long periods away from Imperial borders and supplies, when they return, these Astartes are reputed to be quite terse and short tempered when dealing with humans, preferring to commune with the tech priests of the Adeptus Mechanicus when requesting repairs.

Working in relative isolation from one another, the individual Steel Sentinels vessels have developed unique relationships with the sub-sector's population, with some captains earning a reputation as heroes, while others are seen as taskmasters.

Recent Activities
The Steel Sentinels have recently begun consolidating their forces together into one large fleet, the scattered vessels uniting once more under the directive of Chapter Master Mahar.

Combat Doctrines
"I understand brother...my will is unbroken. I shall Adhere."

- Brother-Sergeant Kandic's final words as he and his squad were overrun by traitor forces

The Steel Sentinels follow the Codex Astartes in much of their campaigns, referring to its wisdom before beginning any engagement. Indeed, careful planning and preparation are the hallmarks of the Steel Sentinels, gathering as much information and data as possible through their Scout Company, occasionally making local contacts and placing agents on planets under their watch.

Adherence to Steel
The practice known as Adherence, a common phrase in the Steel Sentinels refers both to rigidly following through a plan as well as, somewhat counter-intuitively, the exact opposite and producing a spontaneous answer to whatever tactical problem has arisen in the battle. How this is carried out in practice is a chapter that plans extensively for every eventuality with the knowledge that that is simply not enough. Often the allegory of a smith striking a steel blade is used, as the enemy batters the Chapter, like the metal being pounded, sparks will leap out, each one having the potential to create a great fire. Sergeants are often those that have demonstrated this, being able to hold to the plans of their superiors whilst also being capable of producing brilliant strategies in the midst of battle.

This philosophy came as a reaction to the implementation of the Codex Astartes, which limited the numbers of Astartes that could be effectively fielded in a warzone, including officers. Orders then, had to be simple, with as much room for improvisation as possible, seizing opportunities as they emerge rather than being debated or passed down a long chain of individuals.

Long Term Monitoring
An aspect of the Steel Sentinels recruitment, failed aspirant serfs who show particular promise but may not have been suitable for modification due to genetic incompatibility, might be offered a chance to join recruitment missions, establishing small bases of operation on worlds in the Wreath sub-sector that the Steel Sentinels protect. These outposts usually operate in secret without the knowledge of the planetary governor and range from single operatives to cells of a dozen. Usually these outposts are equipped with some method of communication with any nearby Steel Sentinels force, tasked with relying information on the planet and its security. If for any reason these operatives flag a potential threat on the planet the fleet might send scouts to link up with the cell, sharing information and using the base as a safe house to begin investigating any threat.

The cells would additionally keep track of hive gangs and any potential recruits on the planet, relying the information to the fleet in constant reports that the fleet files away for review.

Tempering the Steel
Another phrase used by the Steel Sentinels referring to their use of rolling bombardment as their forces advance, using large scale artillery when possible to cover their landings and assaults. Through careful planning, use of auspexes and orbital surveys the advancing lines of the Steel Sentinels follow just moments after the enemy has been struck by the Chapter's heavy weaponry. The term comes from a comment made by an Ultramarine Captain reviewing an engagement the Steel Sentinels took part in, seeing the firing of such devastating weaponry so close to your own forces as reckless, saying; "You lot will be burned by your own fire.", to which an unknown Steel Sentinel replied; "How else do you expect to temper steel?"

Recruitment
"Dying with honour on the battlefield is all well and good, but you friend will have to settle with a full recovery."

- Brother-Apothecary Craden

The Steel Sentinels are devoted to keeping themselves at full strength, with fleets spending years at high anchor over worlds they guard, harvesting as many potential aspirants as possible from the hives and feudal worlds of the Wreath Sub-sectors. This has allowed them to keep around one thousand Astartes fairly regularly, with the recent call to muster this number is now a set target rather than an optimum goal.

Recruitment worlds
Tuberosum - an agri-world plagued by various warp beasts and monsters that prey on the native human population, defended by a lone Knight Warden. The planet's system was engulfed in a warp storm and suffered a number of daemonic incursions that the Knight was desperately fighting when a Steel Sentinel's vessel arrived in the system to lend aid, hoping that defeating the forces of Chaos the storm might abate. Together the Astartes, the Knight and the local militia, defeated the legions of warp spawn on the planet. Since then the planet has regularly sent its best to become aspirants.

Cask - a feral world, destroyed by a falling Necron Tomb ship that collided with the planet's moon, a large number of the inhabitants were saved and taken aboard the Steel Sentinels Strike Cruiser that pursued the Necron vessel. The majority of the humans, descendants of colonists that set out from Terra millennia ago, were resettled on Tuberosum with the remainder staying with the Astartes to serve their saviours or become aspirants.

Benthos - due to the size of the Steel Sentinels' flagship, it supports a sizable human population that have lived and died performing the same tasks their ancestors did. Some are given the opportunity to become Astartes, though they are always transferred to other vessels within the fleet immediately to begin their testing, severing all ties with their past lives.

Genes seed stability
The gene seed sample that the Steel Sentinels send to the Magos Biologis for monitoring is regarded as quite stable, with only a few minor flaws that are easily managed by the Chapter's Apothecaries. Of these flaws, the most common is an overactive Catalepsean Node, the implant charged with allowing Astartes to stay awake for long periods of time. The primary symptom of this flaw is insomnia, if left untreated for a long period an Astartes might suffer from paranoia or obsessive behaviour. In many cases the Chapter's Apothecaries have placed those suffering the effects into medically induced comas. While this is regarded as a minor issue, it can lead to disruption especially among commanding officers who remain awake for days and days as they oversee the battlefield. Some within the Chapter embrace this trait, with a the tally of hours on sentry duty without rest seen as a badge of honour.

Tactics and Wargear
"Why am I so sure of victory? I have faith in the Emperor of course! Also we have a mile wide line of artillery that's about to blast them back to hell."

- Brother-Chaplain Adrianus at the Siege of Matters Not

The Steel Sentinels utilise a variety of tactics in their wars against the enemies of the Emperor, showing a willingness to experiment with different doctrines of the Codex Astartes. They also keep a vast array of weaponry in their armouries, with a dutiful core of Techmarines tending to the wondrous artifices they hold within their charge.

The Hammer and Anvil
Two common tactics used by the Steel Sentinels are the Hammer and the Anvil, sometimes joined together as one to pulverise the foe. The Hammer consists of the use of Drop Pod Assault comprised of Tactical Marines and Dreadnoughts equipped with weapons capable of disrupting the foe and allowing the Astartes to entrench themselves in what was once the enemy position. The primary aim of this tactic is an overwhelming show of force intended to break moral, seize assets on the ground and deliver maximum damage to the enemy lines to allow allied forces to advance.

The Anvil involves deploying Astartes on the ground and transporting them to the battlefield in Rhinos and Razorbacks and establishing an entrenched position to establish artillery such as Thunderfire Cannons, Rapier Mortar Batteries and Vindicator Siege Tanks, as well as allowing the Chapter's Techmarines a chance to quickly fortify the area against possible enemy counter-attack. Once the lines have been drawn, the Steel Sentinels advance, using their vehicles as mobile barricades and cover against enemy attack as they rush forward seizing ground under a rain of shells from their own lines.

Together the Hammer and Anvil are a devastating combination, usually involving two or more Strike Cruisers working in tandem, with a veteran Captain co-coordinating in orbit and a second taking to the field. Such a show of force would mainly be used when the Steel Sentinels are alone in their theatre of war, where the risk of allies being hit by friendly fire is nil.

Divergence
A tactic reserved for some of the most reviled of enemies; Traitor Marines. These tactics consist of diverging from the Codex Astartes as much as possible under the assumption that either the Traitors once used it themselves or are veterans of the Long War against the Imperium and thus have survived long enough for a Codex Compliant Chapter to have fought them at least once before in the ten thousand years since the Heresy. Thus new tactics must be thought up to counter the renegades, sometimes in the very midst of battle. This might take the form of extensive use of the teleportation facilities aboard the fleet, sending lone Terminator Veterans among the enemy at random for a few minutes at a time before the suit's armour automatically recalls it, with the aim of sowing dismay and confusion as contradictory information diverts forces from key locations. Or in the formation of killteams in the style of the Deathwatch tasked with assassinating the enemy commander or placing melta charges in key locations before the full frontal attack. Often however the particular situation will call for different tactics, and if the commander of the Steel Sentinels' forces decides that the Codex Astartes or other military writings is not applicable then it is up to them to draw up their own plan.

The Protocol
While not a codified tactic, the Protocol refers to a scorched earth policy of destroying any established fortifications or bases of operation to prevent them being seized by the enemy. It is standard practice to use a portion of the company's explosives to rig the command centre to explode should it fall to enemy invaders.

Agents on recruitment worlds and space stations will usually have elaborate traps and defences surrounding their secret cache of communication equipment, all set to explode should any but a member of the Steel Sentinels and their servants (or to the surprise of even the Techmarines of the Chapter, an Inquisitor) attempt to activate it.

Sheathed in Steel
A common practice among the Astartes of the Steel Sentinels is the near constant tinkering and reinforcement of their armour, adding extra plating, redundant battery packs and slots to hold additional ammunition being common features on their worn plate. Seldom are these additions aesthetically pleasing, with only Chapter Veterans having sufficient skill and craftsmanship to enhance their armours looks at the same time as its practicality.

This is believed to foster competitive rivalry between brother Astartes, as each is presented with blank plate armour, which depending on where the fleet the Scout was recently gifted the Black Carapace could range from top of the line plate from a Forgeworld or scavenged pieces from various marks the Chapter has salvaged over the millennia.

This also extends to the Chapter's vehicles which will feature extra plating over much of its surface, sometimes adding half again the weight of the vehicle.

Chapter Monastery and Fleet
"It is said that iron sharpens iron...let us see if steel can't break it."

- Brother-Captain Danos aboard the Strike Cruiser "Mask" in pursuit of an Iron Warriors vessel

Benthos
As a fleet based Chapter, the Steel Sentinels' flagship Benthos, serves as the Chapter's Monastery. A Grand Cruiser class vessel of immense size, seized from Traitor forces during the Heresy War, where it was impounded by the Ultramarines Legion. Thousands of years later it has found its way into the service of the Imperium once again as the flagship of the Steel Sentinels. The Benthos also serves as the Chapter's main armoury, holding the blessed relics and armour the Chapter has maintained over the centuries, with an abundance of Cataphractii Pattern Terminator armour being held there.

Mask
The Vanguard Strike Cruiser Mask serves as the Second Company Command ship, with Brother-Captain Danos directing the trailing fleet the cruiser retains. The Mask served as one of the most public faces of the Chapter, with Danos having a full company able to respond to numerous threats across the Sub-Sector of Wreath throughout the last century, earning a reputation as a saviour as it comes to aid other Imperial forces.

Anaxagoras
Flagship of the 3rd Company Fleet, commanded by Brother Captain Krantor. It is regarded as a particularly ugly vessel, with patch jobs and layers of additional armour added to its frame over the years making it difficult to identify what the original class the vessel even was. It is seldom seen in Imperial space, instead spending much of its time out on crusade.

Tarrasch's Folly
Another Strike Cruiser, the Tarrasch's Folly serves as the flagship of the Fourth Company fleet, commanded by Brother-Captain Tarrin. Like the Mask, the Folly mainly serves as a response vessel, coming to the aid of Imperial worlds.

Gift of Asperity
Flagship of the 5th Company, a Strike Cruiser tasked primarily with overseeing the establishment of long term monitoring stations, escort duties as well keeping vigil over systems under threat of rebellious activity.

Collaboration with other Imperials
When fighting alongside other Imperial forces, the Steel Sentinels would appear like any other Chapter, with only the occasional eccentricity that would set them apart from other Astartes.

Astra Militarum Commanders praise the Sentinels, many of whom claim that they were treated as equals in a battlefield where they had committed the most forces despite the veneration usually expected by other Space Marines, as well as an appreciation of a number of the Marines' willingness to send forces specifically to prevent major losses of life of Imperial servants, an aspect mainly lauded by the line officers.

Adeptus Mechanicus forces praise the 'machine-like' precision of operations when planned in conjunction with the Sentinels, some of which have even learned the binaric cant of the Mechanicus to better communicate with their troops.

Other Space Marine forces find the Steel Sentinels to be easy to work alongside, especially those that adhere closely to the Codex Astartes such as the Ultramarines, which the Steel Sentinels will also comply with fully when such forces are their allies, refraining from any divergent tactics.

Collaboration with the Inquisition, while not common, would usually be on amicable terms, many of the commanders and veterans in the Chapter were once part of the Deathwatch and so have contacts within the Ordo Xenos to pass on reports or warn of impending threats. One particular Inquisitor, known as Marcos the Merciful, has a good relationship with the Chapter, with his network of spies passing on information to the long term monitoring cells that the Chapter might have interest in.

Faith
The Steel Sentinels keep to the original teachings of the Emperor of Mankind, having an extensive archive of historical writings from Remembrancers that sought to bring the Imperial Truth to the Galaxy, the Chapter has seen to the maintaining of this resource with the Librarius being tasked with its protection as thousands of serfs and cherubs scurry about the vaults of the Benthos delivering ancient scrolls and tomes to those that request them. This is not to say there is no faith among the Steel Sentinels, indeed they hold the Emperor in the highest regard and seek to serve His Imperium in the duty they have been tasked.

Chapter serfs are allowed practice whatever version of the Imperial Cult they wish, many finding security in the teachings of the Ecclesiarchy rather than the cold logic of the Chapter Cult, which can barely be called such.

The Chaplains in the Chapter mainly serve as trusted advisors to Captains, as well as leaders on the frontline. Referring to the original Order of Observance issued by Malcador the Sigillite, the Chapter's Chaplains keep a close watch over the Librarians of the Chapter, monitoring for signs of corruption.

Librarius
The Steel Sentinels include a Librarium within most of their vessels, the Benthos in particular having an extensive chamber devoted to training those aspirants with psychic potential covered in hexagramic wards and extensive tomes on the sanctioned arts of the Librarian. The Chapter also has expertise in the divination, geomancy and technomancy disciplines, with most aspirants showing talent for one of these three schools. The Chief Librarian, Brother Galleus, is a powerful geomancer, able to shake apart the foundations of enemy fortifications and carry entire buildings across the battlefield to disgorge the entrenched marines held within.

More than their role in combat, the Librarians of the Chapter have the important role of maintaining the history of the Steel Sentinels within their extensive archives, the nexus of which is held deep within the Benthos. Here the information gathered from Imperial listening posts, intercepted messages and the long term cells monitoring worlds in the Sub-Sector are gathered and ordered to be reviewed by the Chapter's command structure.

Notable Battles
The Bastards' Take 905.M38 - Tracking a band of Chaos Space Marines wearing the colours of the Sons of Horus Legion, the Steel Sentinels uncover a feud between the Black Legion and a group calling themselves the Moravec Covenant, a splinter faction of the Warmaster's Legion who refuse to bow to Abbadon's rule. After establishing a blockade of the Macestus system, the Steel Sentinels manage to corner the feuding Traitorous Marines on the world of Mecestus III where they laid siege to the already weakened forces. Torn between a choice between fully engaging one enemy and allowing another to escape the planet, it was decided that the forces engaging the Covenant would disengage and engage the Black Legion, seen as the greater threat to the system and Sub-Sector. As the Covenant found themselves gaining ground they were hit by mines and automated defense turrets, eventually breaking through to a landing site the Sentinels had been using, their landing craft coming under fire from flakk turrets emplaced around the area. Escaping to low orbit aboard their battered fleet, the Covenant attempted to run the blockade, heading towards a less stable Mandeville point, activating their warp engines amidst a hail of weapons fire. The Steel Sentinels on the planet remained behind to engage the Black Legion, ending in a battle over the same landing site as both sides sought to prevent the other from receiving much needed supplies.

'WAAAGH! of Da' Lukky Boyz 807.M39 - 'A band of Orks, led by the prophecies of a strange blue Weirdboy known as Lukky Jak, direct their lumbering voidcraft towards the Wreath Sub-Sector. In an effort to redirect the WAAAGH! towards the Maelstrom, a series of planets are intentionally fortified despite having no strategic value, going off the belief that the Orks will be drawn towards wherever planets would present the best fight. The Steel Sentinels, who spearhead the operation, suffer great loses as worlds that were only partially prepared for attack are struck by the xenos horde. The plan only partially works, as the Orks go dormant for a period, gathering their strength as more are drawn towards the bizarre philosophies of luck that their prophets spout.

The Defence of Tuberosum 845.M39 - A daemonic incursion onto an Imperial agri-world known as Tuberosum is heralded by a warp storm, preventing the Steel Sentinels fleet from leaving the system. The planet's defence forces are quickly overwhelmed, with only a lone Knight Warden, known by locals as the Prince, still standing to take on the daemonic hordes. A mass drop pod assault rains down on the planet from the Strike Cruiser Mask, creating islands of sanity in a sea of chaos, allowing rag tag groups of the world's survivors being escorted by the Prince to safety. As the Astartes pushed back against the daemons, the Knight emerged, trampling over the warp entities allowing the Sentinels to follow in its wake. Eventually the Sentinels were able to get the Knight to the warp gate that was allowing the daemons to emerge, which it crushed with its massive fist.

The Clash over the Nightforge 850.M39 

Siege of Matters Not 876.M39 - A monitoring station cell reports the presence of Renegade Marines known as the Rust Mongrels on a forgeworld, seeking to loot the planet's riches. Surprising the renegades with unorthodox tactics, the Steel Sentinels surrounded the roaming band of warriors who found the hab-blocks they intended to shelter in devoid of any people, the population having been evacuated to shelters the Steel Sentinels had ordered constructed decades before. Bombarding the enemy, the battle ended in a chase through the close quarters of the streets and ruins of the world's prime hive city.

The False Light 955.M39 - The Steel Sentinels Vessel Mask, encounters a strange phenomenon that appeared to mimic the Astonomican in realspace for a brief moment, visible only to those vessels in a few lightyears around the source, a planet known as Cask, surveyed in the final days of the Great Crusade. There the Chapter discovered a lost colony of humans being set upon by Necrons whose ship had crashed into the planet's largest moon, dooming the fragile world. Clashing with the xenos, with the help of the Explorator fleets of Forgeworld Tarkus and the Achromus 13th Battalion, a large portion of the human population of the system is evacuated. The origins of the strange light is never uncovered.

Notable Members
Mahar Dolsts - The Chapter Master of the Steel Sentinels, Dolst was the Captain of the Fourth Company, the icon of the green wreath which adorns their company banner featured on his custom terminator plate. Attached to his armour he wears a banner gifted to him by the Mechanicus for the defence of a sacred site of theirs. He wields a pair of master-crafted lightning claws, one with a chainfist attachment, the other with a boltgun mounted in the wrist.

Brother-Captain Danos - Captain of the Second Company, Danos has a good relationship with the other Imperial factions within the Wreath Sub-Sector, particularly the tech-priests of forgeworld Tarkus, whom he has fought alongside personally on numerous occasions. His artificer armour comes equipped with a custom build powerfist with two energy prongs able to extend from the knuckles to deliver an extra level of armour penetration beyond that of a normal fist.

Brother-Captain Krantor - Captain of the Third Company, Krantor has gained a reputation as a cruel man willing to enact total war over a planet, demanding that planetary governors and PDF Commanders follow all his orders, that they commit themselves wholly to the war effort, those that resist will find themselves reconsidering their opinion on the front lines. A student of history, Krantor regularly employs tactics developed during the Age of Terra by warlords long dead and seldom checks the Codex Astartes, believing that adherence to a single text would leave the Chapter vulnerable. He wears a set of Cataphractti Terminator Armour, a large two handed blade and a relic volkite weapon from the Great Crusade.

Brother-Captain Tarrin - Captain of the Fourth Company, Tarrin is the youngest captain in the Chapter, elevated to the position following the ascension of Mahar to Chapter Master. He is known to follow closely to the tenants of the Codex Astartes, as well as his adoption of technologies considered "new" by the rest of the Chapter such as grav weaponry and Centurion Warsuits. Along with his Errant pattern armour, Tarrin goes to war armed with a large blade of blue energy capable of slicing through the toughest armour, his enhanced servos allowing him to swing the oversized weapon with ease, with that he carries a combi-grav boltgun.

Brother Gazreal, Master of the Forge - the principal Techmarine among the Steel Sentinels, Gazreal is a master of the arcane arts of the Mechanicus, learning secret techniques on the maintaining of relics and wargear long fallen out of common usage by other Chapters. Gazreal wades into combat with a full servo-harness along with his servitor assistants so that he may tend to the needs of the various machine spirits and ancient dreadnoughts deployed under his supervision.

Brother Galleus, Chief Librarian - Galleus is a powerful psyker, able to create earthquakes and levitate entire hav blocks, he is also able to assess a location's foundations simply by concentrating on it knowing the best places to place a fortification with the sturdiest bedrock. Along with that he serves as the primary recordkeeper for the Chapter, controlling the flow of information to the Command structure, of which he forms an advisory part to.

Brother Antiquin - a psyker adept at divination, Antiquin was joined to the Second Company during the False Light incident, where the veteran saved a village of humans on the planet Cask from being taken by a Necron force, where he was captured by the xenos and dragged back to their ship. It was discovered afterwards that many potential aspirants could be found among the survivors of the attack, a number of which had latent psychic abilities.

Veteran Sergeant Jaegas - a sergeant of a Tactical Marine squad, Jaegus earned a reputation in the Chapter for his good luck after his fight with a Harlequin Troupe Leader, who lashed out at him with a myriad of weapons and complex maneuvers, only for the Eldar to inadvertently impale itself on Jaegus' boltgun's custom bayonet. Later, Jaegus rushed another group of xenos, only for his plasma pistol to overheat, melting through his armour in a burst of energy, the wound would have proved fatal had the Sergeant not packed a small pack of playing cards on his belt that the plasma spent a few precious moments cooking through allowing him to throw off the damaged armour and allow his weapon to cool down.

Hazard Squad - a Tactical Squad of some note within the Chapter, known for their willingness to be dropped right into the enemy lines, taking much enjoyment out of being the first into the fray.

Deathwatch Membership
The Steel Sentinels have a particular hatred for xenos, contending with everything from a number of minor Ork WAAAGH!, hidden Tyranid Hive Ships adrift in space, raids by Eldar and even incursions into Imperial space by a scouting Cadre of the Tau Empire. As such they have a vested interest in monitoring xenos activity in the Imperium, sending as many members to the Deathwatch as possible, with the intent being that they would return with the skills and techniques they learn from the alien hunters to spread to the the Chapter, with the current Chapter Master and Captain of the Second Company both being former members of the Deathwatch.