"You are Astartes indeed, and that will never alter. But you are a Death Guard no longer. You are a ghost, a figure that stands between light and dark, trapped amid the grey. And I have need of such a man."

Malcador the Sigillite, Regent of Terra
Nathaniel Garro Agentia Primus

Ancient Remembrancer's sketch of Nathaniel Garro -- Knight-Errant and Agentia Primus of Malcador the Sigillite.

Nathaniel Garro was originally the Battle-Captain of the Death Guard Legion's 7th Great Company and later became the leader or Agentia Primus of a band of Space Marines gathered from all the Legions known as the Knights-Errant who remained loyal to the Emperor of Mankind and became the core of what would become the Grey Knights.

He was the leader of "The Seventy," the 70 surviving Loyalist Astartes who alone of the Death Guard Legion escaped the massacre of Loyalists at Istvaan III aboard the Imperial Navy frigate Eisenstein to bring word of the Warmaster Horus' betrayal of the Emperor to Terra.

He held to the original tenets of his Legion when many of his Battle-Brothers chose to follow Horus, their traitorous Primarch Mortarion, and First Captain Calas Typhon's decision to serve Chaos and overthrow the Emperor, installing Horus as the true Emperor to rule over the Imperium of Man.

After his arrival at Terra, Garro would be tasked by the Emperor's Regent, the psyker Malcador the Sigillite, with gathering other Loyalist Astartes from all of the Legions, Traitor and Loyalist alike, who would wear the heraldry of the Sigillite himself.

These Astartes would become the core of a new Imperial institution composed of Astartes and Imperial nobles of "an inquisitive nature" that would serve as the precursor of the Imperial Inquisition and the Grey Knights Chapter of Space Marines.



Nathaniel Garro b&w

Battle-Captain Nathaniel Garro of the Death Guard Legion's 7th Great Company.

Like so many of the Astartes of the Traitor Legions who remained Loyal to the Emperor at the start of the Horus Heresy, Nathaniel Garro was born on Terra, in the small techno-barbarian state of Albia, situated in the area of southeastern Europe near what once had been the ancient nation-state of Albania. Garro was one of the few remaining Terran Astartes of the XIVth Legion when it had still been named the Dusk Raiders, so known because of their signature tactic of attacking a foe at nightfall.

Garro had joined the XIVth Legion before men had even known the name of Barbarus, the future homeworld of Mortarion and the Death Guard. In those early years of the Great Crusade, the XIVth Legion had no Primarch but the Emperor himself. The Dusk Raiders had worn armour without the green trim of the later Legion. It was the dull white of old marble, their right arm and shoulders coloured in a deep, glistening crimson. The symbology of the armour showed their foes who they truly were -- the Emperor's red right hand, relentless and unstoppable. Many enemies had thrown down their weapons the moment the sun dipped beneath the horizon, rather than dare to fight them.

But that too had changed. When the Emperor’s sons, the great Primarchs, had been sundered from his side and scattered across the galaxy, the Dusk Raiders joined their brother Space Marine Legions and the Master of Mankind in the Great Crusade that began the Age of the Imperium. Garro had been there as the Emperor crossed the galaxy in search of his lost sons -- Sanguinius, Ferrus Manus, Roboute Guilliman, Magnus the Red and all the rest. With each reunion, the Lord of Mankind gave his sons the command of the Astartes forces that had been created in their image. When at last the Emperor came to Barbarus and discovered the gaunt warrior foundling named Mortarion who lead its oppressed people, he knew he had located the Primarch of the XIVth Legion.

On the day of Mortarion's coronation as Primarch, a good majority of the XIVth Legion had been of Garro's stock, men born on Terra or within the confines of the Sol System, but slowly that number had dwindled, and as new recruits joined the Death Guard's fold they came only from Barbarus.

But by the last days of the Great Crusade in the early 31st Millennium, only a comparative handful of Terrans remained in the Legion. In his darkest moments, Garro imagined a time when there would be none of his kinsmen left amongst the XIVth, and with their deaths the traditions of the old Dusk Raiders would finally fade away. He feared that moment, for when it came to pass he knew that something of the Legion's noble character would die as well.

His refusal to relinquish these old Terran traditions and "high-handed" leadership caused a rift between himself and some of the Barbarus-born captains of the Legion, who often referred to the staunch and reserved Battle-Captain as "Straight-Arrow Garro." Many of the newer Astartes inducted from Barbarus felt that before their Primarch had brought new blood to their Legion, there were many rituals and habits that served only to hold the Death Guard back.

Yet the old ways of the XIVth Legion were fading, and there were few among the senior Battle-Brothers of the Death Guard who deigned to keep the careworn traditions of the Legion alive. The slow shifting of mood had begun in the months following the Emperor's decision to retire to Terra from the Great Crusade after the conclusion of the great offensive against the Orks during the Ullanor Crusade, whereupon he had bestowed the rank of Warmaster upon Horus, the Primarch of the Luna Wolves Legion. The Emperor further compounded this rift by his refusal to recognise the growing fraternity of the warrior lodges within the Legions, despite being offered membership on multiple occasions.

The Death Guard differed from many of their brother Legions in the manner of their command structure and rank system. Tradition had it that the XIVth Legion should never number more than 7 Great Companies, although those divisions held far more men than those of other Astartes cohorts like the Space Wolves or the Blood Angels; and whilst many Legions had the tradition of giving the honorific of "First Captain" to the commanding officer of the elite 1st Company, the Death Guard also held two more privileged titles, to be bestowed upon the leaders of the 2nd and 7th Great Companies, respectively.

Thus, although they held no actual seniority over one another, Captain Ignatius Grulgor of the 2nd Great Company could carry the rank of "Commander" if he so wished, just as Garro, as Captain of the 7th Great Company, was known as "Battle-Captain." Garro's particular honorific dated back to the Wars of Unification, to a moment when the mark of distinction had been handed to a XIVth Legion officer of the 7th Great Company by the Emperor Himself. Garro was proud to bear the honourific centuries later.

Great Crusade

Kalton-Gul Tactical Squad

Death Guard Astartes during the Great Crusade.

Battle-Captain Garro was a seasoned Astartes Veteran of multiple campaigns of Imperial Compliance who had fought besides the Astartes of several other Legions and formed bonds with a select few amongst them. He knew Captain Garviel Loken of the Luna Wolves from when the Death Guard fought alongside them during the Krypt Campaign against the Orks. Garro was also close friends with Captain Saul Tarvitz of the Emperor's Children.

The two Astartes shared a close bond as "honour brothers." There were few men outside the Death Guard that Garro would ever have given the distinction of being called "brother", but Tarvitz was one of them. Tarvitz had earned Garro's friendship during the Preaixor Campaign and proven to him that for all the reputation of Fulgrim's Astartes as overconfident peacocks, there were men amongst the ranks of the Emperor's Children that embodied the ideals of the Imperium. In recognition of their bond, the two Astartes had a small eagle carved into their Power Armour's Ceramite by knifepoint, a sign of the battle debt they owed one another. When the two clasped each other's wrists their vambraces would form the sign of the Imperial Aquila.

Towards the end of the Great Crusade, Battle-Captain Garro earned high accolades during the Jorgall Persecution, for his actions against those psychically powerful xenos when he fought alongside a cadre from the Sisters of Silence. He was singled out by his Primarch Mortarion, who offered Garro the rare opportunity to share a celebratory drink with him. It was said that there was no toxin too strong, no poison so powerful and no contagion of such lethality that a Death Guard could not resist it.

The Death Guard were known to harden themselves through stringent training regimens as Neophyte Astartes, willingly exposing themselves to chemical agents, contaminants, deadly viral strains and venoms of a thousand different shades. They could resist them all. From a set of bowls was mixed and poured dark liquids into a pair of ornate goblets. The senses of the chosen Astartes often rebelled against the odour of the toxins, their implanted Neuroglottis and Preomnor organs rebelling at the mere smell of the poisonous brew; but to refuse the cup would be seen as weakness.

The poured distillate often contained a potent mixture of agent magenta nerve bane, some variety of sword beetle venom, and other, less identifiable compounds. The cups were Mortarion’s, and in each battle where the Death Lord took the field in person, he would select a warrior in the aftermath and share with that man a draught of poison. They would drink and they would live, cementing the unbreakable strength of the Legion they embodied.

Mortarion knew Garro frowned upon such traditions as the cups, but he explained to him that honours and citations were sometimes necessary. Warriors must know that they are valued. Praise from one's peers must be given when the moment is right. Without it, even the most steadfast man will eventually feel unvalued. Mortarion talked to Garro privately, trying to gauge the Battle-Captain and figure out where his loyalties truly lay. The Primarch wanted to ensure that Garro would be loyal to him and the cause of the Traitors when the Warmaster launched his campaign to usurp the Emperor and topple the corrupt Imperium.

Mortarion also wanted to know why the Battle-Captain eschewed membership in the warrior lodge] that had been established within their Legion, a custom that had spread from the Luna Wolves Legion to many of the other Astartes formations. Garro felt that as Astartes, they had been set on a path by the Master of Mankind, tasked to regather the lost fragments of humanity into the fold of the Imperium, to illuminate the lost, castigate the fallen and the invader.

They could only do so if they possessed truth on their side. If they did not do this openly then he had doubt that the XIVth Legion would eventually expunge the fallacies of gods and deities, but they could not bring the secular Imperial Truth to bear if any of it was hidden, even in the smallest part. Only the Emperor could show the way forward. Garro felt that these lodges, though they had their worth, were ultimately predicated upon secrecy and the act of concealment, and he would take no part in it.

Though disappointed by Garro's point of view, Mortarion still hoped to turn Garro to the Traitors' cause. He appointed the Battle-Captain as his Equerry, taking him to an important conclave aboard the Warmaster’s flagship, the Vengeful Spirit, to discuss the upcoming campaign in the Istvaan System. The Primarch hoped to sway Garro’s loyalty towards the Warmaster’s cause.

Istvaan III

Orbital Bombardment

The Warmaster Horus reveals his treachery, ordering the orbital bombardment of Istvaan III.

Garro's 7th Company fought in concert with the Emperor's Children's elite 1st Company against traitorous forces on Istvaan Extremis, the outermost planet within the Istvaan System. Whilst fighting against a powerful Slaaneshi psyker known as a Warsinger, Garro sustained serious injuries; crushing damage to his torso, arm as well as the loss of his right leg from the mid-thigh down. He was only saved from certain death by the timely ministrations of an Apothecary from the Emperor's Children Legion -- their Chief Apothecary, Fabius Bile. Garro's leg was eventually replaced with a bionic leg of excellent quality. Garro was livid, feeling his anger surge each time the new leg made him limp. The minute gyroscopic mechanisms in the limb would take time to learn the motions and kinetics of his body movement, and until they did, he would be forced to walk as if lame.

The Legion’s Apothecaries had not declared him fully healed and therefore Garro was deemed unfit for battlefield operations. His command also remained on limited duty until their commander was fit to reenter combat. As a result, Garro and his company would not be going down to unleash the final assault upon Isstvan III. Those orders came directly from the Death Guard's First Captain, Calas Typhon.

Garro was to be stationed instead aboard the frigate Eisenstein during the assault on Istvaan III, while Commander Inatius Grulgor of the 2nd Company kept a close eye on the Terran-born officer. They were both to be assigned to duty stations with their Command Squads aboard the Imperial warship, where they would supervise its operations. The rest of their Great Companies would remain in reserve. During the assault on Isstvan III and the Choral City, they would provide standby tactical support for the Drop Pod deployment operation, and remain on alert to perform rapid-reaction interdict duties.

Before the mission began, First-Captain Typhon pulled Commander Grulgor aside and spoke to him of their Primarch’s desire to bring Garro to the Warmaster's banner over the Emperor's, but they both knew that Garro would never betray the Master of Mankind. He was too much the Emperor’s dutiful warrior. Realising the First-Captain's intent, Grulgor deduced that the time for the Traitors to act against the Imperium had arrived, as he saw Horus' intention emerging in the unusual pattern of mission assignments on Istvaan III granted to specific units from the Legions, instead of complete companies.

Grulgor realised that the Warmaster sought to isolate those elements of the soon-to-be Traitor Legions that did not share his convictions. When the turning point arrived, Typhon informed Grulgor that there were certain duties that Horus would want him to perform. The Commander relished his part in this conspiracy against Garro, whom he had long found insufferable.


The Eisenstein was an unremarkable Imperial starship, an older pattern of vessel in the Frigate tonnage grade, just over two kilometres in length from bow to stern. It bore some resemblance to the newer Sword-class craft, but only inasmuch as most Imperial starships shared a similar design philosophy. Garro knew that they would not be making much history on this day.

Their Primarch had ordered that they maintain orbit at high anchor and watch for enemy ships that might attempt to escape Istvaan III under cover of the ground assault. Garro became suspicious of Commander Grulgor’s manner as well as their orders to change position and drop into lower orbit, deepening the uneasy feelings he had about the entire operation. Though the Battle-Captain suspected something was terribly wrong, he could not place his finger on what it was. Had they been carrying Drop Pods and Astartes for a second assault wave, then the reasoning behind the orders would have been clear, but the Frigate was not configured for those sorts of operations. It was, in the most basic sense, only a gun carriage.

Garro's Legion serf, the housecarl Kaleb Arin, made his way down to the launch bay to spy on Commander Grulgor on behalf of his lord and find out exactly what they had transported aboard the Eisenstein. When he saw them unload a crate and opened it to inspect its contents, the dark liquid contents contained within the glass pods represented something utterly lethal. With clarity he suddenly realised the threat that Grulgor's cargo presented.

He also observed the work gangs busy detaching the warhead cowlings from thruster-guided glide bombs, exchanging the explosive charges inside for the globes of liquid. The 7th Great Company's Apothecary, Meric Voyen, also had his suspicions, and had also stealthily made his way to the launch bay to investigate. He saved the housecarl from narrowly being captured by Grulgor's men.

Kalab shared with the Astartes what he had witnessed. Digesting what the housecarl told him, Voyen realised with growing horror that the deadly cargo were Life-Eater virus bombs -- an engineered viral strain of such complete lethality that it could only be deployed in the most extreme circumstances, usually against the most foul xenos. The Life Eater virus was a true weapon of mass destruction, a world-killer. Only the largest capital ships were permitted to carry them in their armouries. Grulgor had brought the virus bombs over from the Death Guard capital ship Endurance.

During the opening stage of the first assault wave, the Eisenstein picked up an unscheduled movement in their battle sector. They received a signal from another ship leaving the confines of the Lord Commander Eidolon’s ship, the Andronicus, from the Emperor Children’s Legion. At first they thought that it might be the insufferable Eidolon making an unscheduled mission flight down to Istvaan III's surface, eager to take part in the glory. But they soon realised that the lone craft was a Thunderhawk, and behind it a cluster of Raven interceptors were in an attack delta formation.

Confused by this turn of events, the Andronicus sent the Eisenstein a message ordering it to destroy the Thunderhawk on sight, as it was acting against the Warmaster's commands and was to be considered a Renegade. At the same time, the Eisenstein also received a message from the Thunderhawk. The occupant was none other than Garro's honour brother, First Captain Saul Tarvitz. Garro's mind was awash with confusion: a rogue Thunderhawk, the signal from Eidolon, the incredible command to terminate the fleeing vessel and the ranking Astartes officer aboard it.

Was this some kind of test? Some bizarre sort of battle drill to assess the mettle of the Eisenstein’s command crew? Or could it be true that Saul Tarvitz had indeed turned Renegade and was fit only for execution? If it was possible for Istvaan III’s Imperial Governor Vardus Praal to turn against the Emperor, then perhaps an Astartes might do the same. Tarvitz’s next message was a dire warning, telling Garro that the entire operation was treachery. Horus had betrayed the Emperor! The fleet was going to bombard the planet’s surface -- and the Astartes upon it -- with virus bombs!

Tarvitz swore on his life that he would not lie to his honour brother. Every Astartes on Istvaan III was going to die. Coming to a quick decision, Garro acted of his own volition and ordered the Eisenstein to destroy the Thunderhawk. But in actuality he altered the firing coordinates so that the Frigate destroyed the lead Raven interceptor, whose explosion caught the other interceptors in its wake, due to their close formation. As Tarvitz's Thunderhawk was close to Istvaan III's atmosphere, he used the sensor disruption to slip away. Garro's men had just witnessed their commanding officer disobey a direct order from their superior.

This was dereliction of duty, grounds for severe chastisement at a minimum. If the Warmaster learned of the Battle-Captain’s insubordination, it would taint them, and the entire Death Guard. Nevertheless, Garro ordered the ship’s crew to contact the Andronicus and inform them that the rogue vessel had been destroyed, and the explosion claimed their pursuit ships as well. Though some of his men were made uneasy by the Battle-Captain’s actions, Garro explained to them that as an honour-brother, Tarvitz only spoke the truth, and his words were no falsehood.

Garro soon saw the larger picture. The sheer horror of it, echoed inside his thoughts. Betrayal. The idea of it made him go weak. And with that realization there came another. If Horus had prepared this treachery, then he had not done it alone, it was too big, too monumental an endeavour even for the Warmaster to have managed by himself. Garro realised that Horus’ Primarch brothers would have taken part in this treachery as well: Angron, ever ready to take any path that led him to more bloodshed; Fulgrim, convinced of his own superiority and perfection over all, and the Mortarion himself, in secret conspiracy with the Warmaster due to an old grudge he had long held against the Emperor.

To compound matters further, Garro’s housecarl arrived on the bridge of the Eisenstein and informed his lord that Grulgor and his men were loading the main guns with Life-Eater virus bombs. With only Apothecary Voyen, Battle-Brother Sendek and his housecarl, Garro confronted Commander Grulgor and his entire command squad and a handful of naval crew. When confronted by Garro, Commander Grulgor made a seditious announcement, explaining that the Emperor had abandoned them, leaving the Legions behind so that he could flee back to Garro’s precious Terra. He had sold off the Space Marine Legions' birthright to a council of weak-willed fools and politicians, taken civilians who had never known hardships or the kiss of war, making them lords and lawmakers in the Primarchs' stead. The Emperor held no authority over the Death Guard. Only Horus and the Death Lord could command them. What they were doing on Istvaan III, they did by the will of Horus and Mortarion.

Eisenstein Gas Attack

Ignatius Grulgor's traitorous subordinates suffer a grisly fate in the form of the Life-Eater Virus.

The three Loyalist Astartes and the human housecarl leapt at their foes with righteous fury. During the ensuing melee, the housecarl saw Commander Grulgor taking aim with his Bolt Pistol at Garro while he was preoccupied fighting off one of his men. Realising the immediate threat, Kaleb instinctively fired his Stub Gun, his shot released an instant before Grulgor's finger tightened on his trigger. The stub-bullet from the handgun struck the frame of Grulgor’s Bolt Pistol, ricocheting off a girder near Garro’s head. Reacting with preternatural speed, Grulgor turned and threw his Combat Knife at the housecarl, killing him. Grulgor's errant Bolter round presented a new threat, as it had ricocheted off the metal bulkhead and into one of the virus warhead spheres, releasing its deadly cargo. Using the last of his ebbing strength, Kaleb launched himself forward and hit an emergency release switch. Garro flung himself under the closing blast shield door, landing hard and rolling out to where Voyen and Sendek were crouched in the next compartment. The hatch was proof against the virus. The housecarl had saved their lives, as well as the ship, at the cost of his own. Grulgor and his men suffered the lethal effects of the Life-Eater pathogen and died screaming in agony.

Garro explained to the rest of his men his confrontation with Grulgor and the virus bombs. He also told them of Grulgor's declaration against the Emperor and the horrifying results of the ensuing melee on the gunnery decks. He continued to explain to his horrified men the entire truth. Grulgor and Eidolon were not two errant souls pursuing some personal agenda, but soldiers in a war of betrayal that was about to unfold. What they had done was not of their own volition, but under the orders of the Warmaster himself. Horus, with the support of Angron, Fulgrim, and though it sickened him to say it, their own Primarch Mortarion, had done this. As a lodge-brother, Voyen confirmed Garro’s words. There has been talk of the Warmaster at second- and third-hand in the lodges. Talk of how far away the Emperor was and of discontent over the commands of the Council of Terra. The tone of things had been strained ever since Horus was injured at Davin, after he returned from his miraculous healing at the hands of the shamans of the Temple of the Serpent Lodge. Horus had personally chosen all the units for the assault on the Choral City. He picked only the Astartes of the gathered Legions who he and his brothers knew would remain loyal to the Emperor. The virus bombing would rid him of the only obstacle within the Legions to open insurrection against the Imperium. Had Garro not been grievously injured on Istvaan Extremis, he had no doubt that he would be alongside their fellow Loyalists below on the planet’s surface, unaware that a sword was poised at their necks. The turn of events had played in their favour, and they had to seize the opportunity in the name of the Emperor.

Flight of the Eisenstein

"His dreams and hope are in ruin, his trust proved false, and his brightest son fallen to darkness. These are bitter tidings, a nightmare made flesh, but they must reach the Emperor."

— Nathaniel Garro, Battle-Captain of the Death Guard
Garro-Hero of Istvaan

Battle-Captain Nathaniel Garro.

With the remaining Loyalists aboard the Eisenstein, Garro was determined to flee the Istvaan System and make for Terra. Now fully aware of the traitorous actions of Horus and his accomplices, Garro had his men make an Oath of Moment upon his Power Sword Libertas. The Death Guard Astartes all swore to dedicate themselves to the safe carriage of the warning of Horus' betrayal to Terra, no matter what forces were ranged against them. Garro had considered briefly the idea of opening up all of Eisenstein’s Vox transmitters to maximum power and broadcasting the truth of the treachery across the entire 63rd Expeditionary Fleet. There were noble men out there, he was sure of it, warriors like Loken and Tarik Torgaddon in the Warmaster’s own Sons of Horus Legion, and Macer Varren of the World Eaters. If only he could contact them, save their lives; but to do so would have meant suicide for everyone on the Frigate.

Every minute they kept their silence was a minute more for Garro to plan an escape with the warning. Loken and the other Loyalists would have to find their own path through this nightmare. The message was far more important than the lives of a handful of Astartes. Garro only hoped that once his mission had been fulfilled he might see them again, either back on Terra at the end of their own escape or here once more with an Imperial reprisal fleet at his back. For now, those Astartes were on their own, as were Garro and his warriors. During the bombardment of Istvaan III with the virus-bombs, the Eisenstein picked up another signal. It was another Thunderhawk on an intercept vector with their ship. It belonged to the Sons of Horus, assigned to the Vengeful Spirit. The pilot identified himself as Third Captain Iacton Qruze, formerly of the Sons of Horus. He claimed to be no longer part of his Legion as he could no longer be a party to what Horus was doing. Garro let the Thunderhawk land upon the Frigate. It bore three refugees from the slaughter of civilians that Horus had unleashed upon his flagship; the Luna Wolf Iacton Qruze, Kyril Sindermann – a high-ranked Iterator, the Remembrancer Mersadie Oliton – and the former Remembrancer Euphrati Keeler – now regarded as a Living Saint by those who believed in the dictates of the Lectitio Divinitatus, the cult first founded, ironically, by the Primarch Lorgar of the Word Bearers Legion that held the Emperor to be divine. Garro granted them sanctuary. When Garro spoke with Keeler afterwards, their conversation strengthened his conviction and growing belief in the Emperor's divinity.

Garro knew his lightly armed Frigate was no match against the powerful capital ships of Horus’ blockading fleet. At the time, the Eisenstein was close to the rear edge of the fleet pattern. The ship’s captain took the liberty of informing the fleet master’s office that they were suffering a malfunction in one of their tertiary fusion generators. It was standard naval procedure for a ship under those circumstances to drop back from the main formation, to prevent other vessels being damaged in case of a cascade failure and core implosion. But the Loyalists knew that the ruse would not last for long. For they would be undone the moment they fired their main engines.

Realising something was amiss, First-Captain Typhon aboard the massive Death Guard Battleship Terminus Est moved to intercept the small Frigate when he had received no word from his usually boisterous subordinate Grulgor. He gave chase as the Eisenstein attempted to evade the guns of his ship. The frigate sustained severe damage from the Terminus Est's massive guns batteries as it sped past. The crippled ship limped away from Istvaan III. It was severely damaged, and all of its Astropaths had perished in the firefight and their lone Navigator was mortally wounded. The ship was incapable of interstellar communication and had little chance of successfully navigating its way across the Immaterium, but Garro ordered the vessel to make a blind Warp-jump in order to save the lives of everyone aboard. Once inside the Warp, the damaged Eisenstein attracted the attentions of the Chaos God Nurgle, the Plague Lord, who had already claimed the Death Guard Legion as his future champions and had no desire to see Horus' rebellion against the Emperor suffer a setback. Because the Eisenstein's Gellar Field had been weakened by the damage the starship had sustained during its flight from the Istvaan System, the Dark God was able to insinuate his malign influence into the vessel. Nurgle's power resurrected Grulgor, his dead Astartes and the ship's crew who had sided with him, creating the first Plague Marines. The ensuing battle between the infected Warp creatures and the Loyalist Death Guard aboard the ship resulted in the death of the vessel's only Navigator. Grulgor, using a Plague Knife, managed to infect a member of Garro's command squad, the young Battle-Brother Solun Decius, with the terrible daemonic disease known as Nurgle's Rot, and almost triumphed over Garro. However, Garro ordered the Eisenstein to make an emergency transition out of the Warp. Without access to the infernal power of Nurgle sustaining them within the Immaterium, Grulgor and his corrupted brethren were killed, their souls sucked back into the Warp, though Grulgor would later be resurrected once more as a powerful Daemon Prince of the Plague Lord.

Stranded hundreds of light years from any stretch of inhabited space, Garro ordered the Eisenstein's captain to overload the Frigate's Warp-Drive and then jettison it out into space. Garro hoped that the detonation of the Warp-Drive would produce such a powerful shockwave in the Immaterium that any passing Imperial starships might be willing to stop and investigate. The plan would also guarantee that if no rescuers appeared, the Eisenstein would never reach another destination and its crew and passengers would die in the black void of interstellar space. However, the ensuing explosion of the Warp-Drive echoed across the Empyrean and acted as a beacon for the Primarch Rogal Dorn and the fleet of his Imperial Fists Legion, who had been becalmed by Warp Storms unleashed by the gathering power of the Dark Gods as the Horus Heresy began. The Imperial Fists were already on their way back to Terra on the order of the Emperor. Dorn rescued Garro and his warriors and took them to Luna aboard the Imperial Fists' great mobile fortress-monastery, the Phalanx. While initially reluctant to the point of outraged violence to believe Garro about his brother Horus and the other Primarchs' betrayal of the Emperor, once faced with overwhelming evidence from multiple sources, including the testimony of Iacton Qruze, a member of Horus' own Sons of Horus Legion, he eventually relented and the Navigators of Dorn's massive fortress ship made their way to the Sol System where Dorn would inform his father the Emperor of this dreadful news.


Garro vs Lord of Flies

Battle-Captain Nathaniel Garro confronts Solun Decius in his daemonic form as the "Lord of Flies".

After arriving in the Sol System with the news, Garro, his fellow Death Guard Astartes, Euphrati Keeler, and Iacton Qruze were all placed in a fortress on Luna that belonged to the Sisters of Silence while the Emperor determined whether they were truthful or were simply further pawns of the Chaos Gods. Even upon reaching Luna, and with the news of the betrayal delivered, Garro's trials were still not over, as one of his Astartes, Solun Decius, had become infected with Nurgle's Rot aboard the Eisenstein. Wracked by constant pain, Solun finally gave in to the temptations of Nurgle to ease his suffering and allowed his corrupted body to be possessed and mutated by a Greater Daemon of Nurgle known as the Lord of the Flies.

His body was twisted by the possessing entity into a hideous daemonic form. In this state, Solun killed the two Astartes who had been conducting the death vigil over his prone form. The Lord of Flies went on a killing rampage throughout the fortress. Garro was forced to battle him throughout the Sister of Silence's citadel and out onto the barren, airless surface of Luna itself. He eventually bested the daemon who had once been his trusted comrade and banished the hideous entity he had become back to the Warp.

Afterwards, Garro, Qruze and the Sister of Silence Amendera Kendel were approached by Malcador the Sigillite, the Regent of Terra, and told that the Emperor needed them to form a new Imperial organisation, outside the boundaries of the existing Imperial bureaucracy, which would utilise " and women of inquisitive nature, hunters who might seek the witch, the traitor, the mutant, the xenos." The Emperor had foreseen that the end of the Horus Heresy would cost him greatly, so much so that he would no longer be able to take an active hand in Mankind's survival.

Yet he also knew that the threat of Chaos would not see defeat with Horus, but would continue to haunt humanity. The very nature of the Horus Heresy had proven that the Space Marines were not immune to corruption as the Emperor had once hoped. So the Emperor set his hand to plans that would win a wider victory from the ashes of a most personal defeat.

Malcador the Sigillite, closest of the Emperor's servants, was ordered to scour the galaxy for those that would be found worthy to help save the future of humanity. This was a monumental task made all the more difficult by the anarchy created by the Warmaster's insurrection. That is how the Sigillite came to be on Luna, and the fate of Battle-Captain Garro became inextricably intertwined with the future survival of all Mankind.

Under the Sigillite's own seal, Garro was tasked with finding 7 other Loyalist Astartes from amongst both the Loyalist and Traitor Legions who were utterly devoted to the Emperor and his Imperium in body and soul. These Space Marines would eventually form the core of what would later evolve into the Grey Knights Chapter of Astartes, the Chamber Militant of the Inquisition's Ordo Malleus. The Inquisition had been born in the fires of betrayal.

Legion of One

"My name is Nathaniel Garro, and I am a Legion of One."

— Former Battle-Captain Nathaniel Garro, servant of Malcador the Sigillite
3. Cpt. Garro - The Sigil of Malcodor

Battle-Captain Garro receives the personal sigil of Malcador the Sigillite, the founding moment of the Inquisition.

After arriving on Terra at Malcador the Sigillite's invitation to begin his quest, Garro's Power Armour had all of its Death Guard regalia removed and replaced with the personal sigil of Malcador, a stylised letter "I" with three horizontal lines through its centre, the icon that would later become infamous across the galaxy after the Heresy as the Rosette of the Inquisition. During his mission for the Sigillite, when questioned as to which Legion he belonged to, Garro consistently referred to himself as a "Knight Errant" and the member of a "Legion of One." Garro's first mission was to the war-torn Calth, a battle-scarred Agri-world located in the Veridian System.

The Loyalist XIIIth Legion, the Ultramarines, were engaged against their treacherous former brethren from the XVIIth Legion, the Word Bearers, in a great contest of the Heresy known to history as the Battle of Calth. Garro slipped past the Word Bearers' orbiting fleet and down to the surface of the war-ravaged planet. He was looking for the Ultramarines' 21st Company, under the command of Captain Erikon Gaius. The 21st Company had been last sighted on the western outskirts of the city of Numinus.

They had been at the forefront of the first Word Bearers assault and it had been their burden to witness the deaths of too many of their Battle-Brothers at the hands of the Traitors and their daemonic allies. They were now a company in name only. Their captain -- the Hero of the Hadier Uprising, Gaius the Strong, Gaius the Unflinching, had rallied them in the face of the brutal losses. With words and deeds he had led them into the fray, and they claimed back in blood a steep price from the Traitors, but not enough. They were cut off from their kinsmen, holding one of the mag-lev railroad approaches to Numinus City.

"You court death, Garro, like some ancient Knight-Errant."
-"That's as good a title as any, Brother.

— Exchange between former Ultramarines Librarian Tylos Rubio and Nathaniel Garro during the Battle of Calth

Garro sought out Battle-Brother Tylos Rubio amongst the Astartes of the 21st Company, an extremely powerful psyker who had once been a Codicier of the XIIIth Legion before the Emperor's formal decree at the Council of Nikaea had banned the Space Marine Legion’s use of psykers, including their own corps of Librarians. Many resented the Decrees of Nikaea, but honoured their oath to the Emperor and surrendered their Librarian panoply and wargear, returning to the lines as ordinary Battle-Brothers.

Captain Gaius had been killed in a Word Bearers' assault when a large force of Traitor Marines and Chaos Cultists nearly overwhelmed the 21st Company's battle lines. Garro arrived before the next assault and found Brother Rubio. He explained to the perplexed Ultramarine that he was there on the orders of Malcador the Sigillite and that Rubio must come away with him. Rubio refused to leave his Battle-Brothers in the face of annihilation unless so ordered by the Emperor himself. Much to Rubio’s surprise, the honourable Garro respected his decision and agreed to stand and fight with him against the Word Bearers.


Battle-Captain Nathaniel Garro wields his ancient Power Sword Libertas during the Calth Atrocity.

In the final assault, the Ultramarines were driven back in the face of overwhelming numbers, and sought cover within a cave. They were hard-pressed by the elite Word Bearers' Cataphractii-armoured Terminators. Brother Rubio was sorely tested, forced to restrain from using his innate psychic abilities, bound by his sacred oaths to the Emperor, even though he knew that by doing so he could have saved the lives of many of his fallen Battle-Brothers.

Facing imminent death, Rubio felt that he had no other choice and unleashed a powerful psychic attack, driving the enemy back with the full force of his powers. The tunnel collapsed in the process, burying the attacking Word Bearers Cataphractii under tons of rubble. The survivors of the 21st Company had been saved and the sole passage to Numinus had been denied to the enemy. The cost of using his powers had cost Rubio dearly -- his honour before his Primarch and his Emperor. Garro told him to be grateful that he had saved his Brothers' lives.

As he approached his fellow Ultramarines, they averted their eyes and as one turned their backs, shunning him. Rubio had disobeyed a Decree Absolute of the Emperor, and for that, there was no forgiveness. Garro drew his sword Libertas and Rubio spun at the sound of it, fixing Garro with a furious glare. Garro held the sword out, the point down towards the ground. He had Rubio place his hand upon the blade to take an Oath of Moment, to dedicate himself to the orders of the Regent of Terra and put aside all other claims upon his honour. Rubio swore upon the blade, for he had little other choice.

The next Astartes that Garro recruited was Captain Macer Varren, a former Battle-Brother of the XIIth Legion, the World Eaters, who had turned Traitor to the Emperor and followed Horus in his madness. Like Garro and Death Guard warriors, Varren too, had forsaken his own kinsmen after they swore fealty to the Warmaster and the Dark God Khorne. The lord of his Legion, the gladiator Primarch Angron, had sent his personal guard to kill Varren for his refusal to join the World Eaters in their sedition against the Emperor. Varren escaped with his life, and an embittered heart. Garro had offered him a new role as one of Malcador's operatives, but in truth, the duty sat poorly with him. Quick to anger like all World Eaters, he longed to be out in the thick of the war, facing his former Battle-Brothers. He lacked the cool detachment of the Death Guard or the stoicism of the Ultramarine Librarian Tylos Rubio.

The last of the seven warriors that Garro was ordered to recruit was Garviel Loken, once a captain and member of the Mournival of the Sons of Horus. Though it appeared that he had perished during the final bombardment on Istvaan III, he had somehow managed to survive on its blighted surface in the ruins of the Choral City for several years after the Traitor Legions had moved on and the larger tragedy of the Horus Heresy had consumed the galaxy. The Warmaster’s insurrection had long since moved onwards towards other sectors. The world of Istvaan III was now a desolate and barren graveyard planet inhabited only by Plague Zombies raised by the lingering taint of Nurgle which had consumed the world after the Life-Eater virus had destroyed all life upon its surface.

Loken had been driven mad by the horrors he had experienced and believed that he had been rejected by Death itself. He experienced a form of amnesia and could no longer recall his own name, taking upon himself the new identity of Cerberus, believing himself to be the sole remaining Loyalist in the galaxy and champion of the Emperor until he was confronted by Garro.

After their arrival on Istvaan III by Thunderhawk, Garro, Rubio and Macer Varren encountered a handful of what they believed to be human survivors who spoke of a beast that hunted them. Taking matters into his own hands, Garro went to the lair of the so-called beast of Istvaan III, and on discovery of the long-dead corpse of Tarik Torgaddon, he was attacked by the unkempt, nearly-psychotic "Cerberus."

After a lengthy battle, during which Cerberus escaped, Garro and his companions discovered that the human "survivors" of the virus-bombing of Istvaan III were in fact daemonhosts who had been transformed into undead Plague Zombies of Nurgle when the virus-bombing had weakened the barrier between the Immaterium and Istvaan III, allowing the Plague Lord's influence to reign supreme. Garro and his Loyalist Astartes managed to defeat the foul creatures with the aid of Cerberus; however, once the undead had been destroyed, Garro and Cerberus had one more one-on-one combat match, as Loken perceived the group of Astartes as Traitors who had come to kill him.

It was during this final fight that Garro managed to reach through the amnesia and fractured awareness of Cerberus to the core of the good man that remained deep within his psyche, reminding him of who he truly was, and that the Emperor still had a use for him in rooting out the corruption that was staining the Imperium. Aware of his true identity once more and how he had come to be stranded amidst the ruins of the Choral City of Istvaan III, Garviel Loken joined Garro and his team. With his assemblage of warriors now complete, Garro and Loken left Istvaan III for Luna to receive their first mission from Malcador the Sigillite.

Laying the Foundations

Garro Knight Errant

Nathaniel Garro, arrayed in his new Mark VI "Corvus" pattern Power Armour, stands resolute.

Acting as the Sigillite's Agentia Primus, Garro continued to scour the battle torn worlds of the Imperium for the men and women upon whose shoulders the burden of the future would be placed. This would have been no easy task in the calm of peace, but amidst the anarchy of the Horus Heresy it was almost impossible. By the time he returned to the Sigillite, Terra itself was under siege by the forces of Horus, and only through the most artful of subterfuges was the Sigillite and his recruits able to pass unscathed through the battlelines and come unharmed and unseen before the Emperor. Malcador brought twelve robed figures before the Master of Mankind.

Of these twelve, four were Imperial lords and administrators that possessed the prerequisite inquisitive nature and unyielding strength of mind. The other eight were Astartes. Some hailed from the Traitor Legions that had forsaken their oaths of fealty to the Emperor in favour of the dark promises of the Warmaster Horus, but these exceptional Battle-Brothers had never lost their faith and loyalty, fighting the heresy from within.

Garro Sword of Truth

Agentia Primus Nathaniel Garro leads his fellow Knights-Errant, including Tylos Rubio and Macer Varren, in the prosecution of their duties during the Horus Heresy.

When last they had met, the Emperor had commanded Malcador to gather together a group of people whose loyalty to Him and to the Imperium was unquestioning. This he had done. The Sigillite had laboured long and hard to find those he thought would be suitable. He had personally overseen every aspect of the exhaustive tests to which the prospective candidates had been subjected and could vouch for his recruits' character, loyalty and strength of mind. Their unflinching loyalty and possession of many paranormal skills would serve the Emperor well. The Emperor was greatly pleased, for the Sigillite had chosen well. Garro's ultimate fate after the Horus Heresy is currently unknown.


Garro possessed a patrician aspect, its roots dating back to the warrior dynasties of ancient Terra. He was pale-skinned, but without the pallidity of his brother Astartes who hailed from the Death Guard’s cold and lethal homeworld of Barbarus. He had old eyes in a face that, despite its oft weary countenance, seemed too young for them; his head was hairless and patterned with pale scars.

In battle, the Battle-Captain wore Mark IV Power Armour. On the chest of Garro's power armour was a brass cuirass that rested there. This was a ceremonial piece that Garro wore only in combat or upon formal occasions. In tandem with the honour-rank of Battle-Captain, the decorative over-sheath sported an eagle, wings spread and beak arched, sculpted from brass as if about to take flight from the chest plate.

Similarly, the rear of the cuirass had a second eagle as a head-guard that emerged from the shoulders when worn over the backpack of Astartes armour. What made this piece unique was that its eagles differed from the Emperor's Aquila. While the symbol of the Imperium of Man had two heads, one blinded to look at the past, one sighted to see to the future, the Battle-Captain’s eagles were singular.


Nathaniel Garror Hand of Malcador

Nathaniel Garro, clad in ornate MK IV Artificer Armour, bearing the symbols of the Sigillite and protected by technologies and artefacts both wondrous and guileful.

  • Artificer Armour - Garro originally wore a suit of Mark IV Imperius Maximus Pattern Power Armour in Death Guard Legion colours. Garro's Power Armour bore an ornate cuirass etched in brass and gold. This was a ceremonial piece that Garro wore only in combat or upon formal occasions. This decorative over-sheath sported an eagle, wings spread and beak arched, sculpted from brass as if about to take flight from the chest plate. After he fled Istvaan III and was charged by Malcador the Sigillite with a new purpose, he was outfitted with Mark VI Corvus Pattern Power Armour, the most advanced wargear yet created at that point in the Heresy for the Astartes. Besides still bearing the ornate cuirass and the eagle behind his helm, there was absence of all other detail. His armour was a uniform stone grey from helm to boot, bereft of all iconography. Sigils of echelon or honour of Legion and fealty were absent, save for a hidden rune upon his shoulder plates; a stylized High Gothic letter "I" etched into the metal of the Ceramite, the mark of Malcador the Sigillite, the Regent of Terra and Adjutant to the Emperor. In later times, this rune would be recognized as the infamous Rosette of the Imperial Inquisition.
  • The Aquila Imperator - Similarly to the ceremonial eagle worn on his armour's chestplate, the rear of the cuirass had a second eagle as a head-guard that emerged from the shoulders when worn over the backpack of his armour. This was known as The Aquila Imperator, an archaic device that protected Garro similarly in function to an Iron Halo. This device emitted a very strong gravitic conversion field around its wearer, which made his armour even harder to pierce with enemy weapons. In addition, it also provided its wearer with immense resilience to even the most potent weapons on the battlefield.
  • Falsehood - The Knights-Errant were gifted by the highest offices of the Mechanicum with many technological artifices, one of the most wondrous and guileful of which was known simply as "Falsehood." Such devices took many different forms and had varying effects, but that used by the Knights-Errant in open battle projected a psycho-luminal sphere about them that distorted their appearance, allowing them to infiltrate the battlefield unseen and, even once detected, made it all but impossible for a foe to draw a bead upon them.
  • Libertas - In battle, Garro bore the ancient Power Sword Libertas. There were no visible imperfections visible in the crystalline matrix of its monosteel blade. It is said that this masterfully wrought broadsword was constructed from remnants of a far older device, a weapon so ancient it predates the fall of Mankind and the coming of Old Night. Whatever the truth, Garro wielded it against countless xenos foes throughout his service in the Great Crusade and, tragically, must now use it to spill the blood of his erstwhile brother Legiones Astartes.
  • Paragon Bolter - The Knights-Errant of Malcador were outfitted with the finest crafted panoply of arms and armour that the Sigillite's household could procure, the plain grey heraldry belying the peerless quality of the underlying workmanship.
  • Master-Crafted Bolt Pistol
  • Frag & Krak Grenades

Legion Serf

  • Kaleb Arin – Kaleb was Battle-Captain Garro’s Equerry and Housecarl. Kaleb was a former Aspirant of the XIVth Legion who had failed the series of trials required for those who wished to become full Battle-Brothers of the Death Guard. Those Aspirants that failed largely chose to accept the Emperor's Peace over a return in dishonour to their clans on Barbarus. But not all, as some lacked the strength of will even for this honour. Through some of the Legions made use of these throwbacks, it was not the Death Guard way. Thus, Battle-Captain Garro, as was his right, saved the failed Aspirant and offered him a place within the Legion as a serf. Kaleb loyally served his lord for many decades, and like Garro, held to the old traditions of the Dusk Raiders. Kaleb was also a secret adherent of the holy teachings of the Lectitio Divinitatus, the sacred tome written by the Primarch Lorgar that extolled the virtues and divinity of the God-Emperor. During the battle of Istvaan III, Kaleb was the one who discovered Commander Grulgor's treacherous intentions, when he saw that he was unloading crates of Life-Eater virus warheads. The housecarl immediately rushed to the bridge and warned Garro of Grulgor's duplicity. During the ensuing battle between Garro and Grulgor's men, an errant shot from the traitorous Commander ricocheted off the ship’s bulkhead and struck one of the deadly containers, releasing the deadly pathogen. Kaleb sacrificed himself in order to ensure that Garro could fulfill his destiny in the name of the divine Emperor.



In the various Black Library audiobooks, Nathanial Garro is voiced by Toby Longwirth.


  • Index Astartes III, "The Lost and the Damned - The Death Guard Space Marine Legion"
  • Flight of the Eisenstein (Novel) by James Swallow
  • Garro: Oath of Moment (Audio Book) by James Swallow
  • Garro: Legion of One (Audio Book) by James Swallow
  • Garro: Sword of Truth (Audio Book) by James Swallow
  • Garro: Shield of Lies (Audio Book) by James Swallow
  • Garro: Ashes of Fealty (Audio Book) by James Swallow
  • Vengeful Spirit (Novel) by Graham McNeill
  • Forge World - Nathaniel Garro, Hand of the Sigillite
  • Forge World - Horus Heresy Datasheet, Nathaniel Garro
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