Roboute Guilliman: The Triumphant Return of the Avenging Son

Roboute Guilliman: The Triumphant Return of the Avenging Son

Roboute Guilliman, known as the “Avenging Son,” is the primarch of the Ultramarines Legion of Space Marines and the current Lord Commander of the Imperium. Created by the Emperor of Mankind to be a superhuman military commander, Guilliman was scattered through the warp as an infant and landed on the world of Macragge.

There he was discovered by its ruler Konor, who adopted Guilliman as his son.

Guilliman quickly proved himself a prodigy and mastered all manner of academic and military disciplines. After his adoptive father was assassinated in a coup, Guilliman took control of Macragge and transformed it into a prosperous, well-defended realm.

When the Emperor arrived years later as part of the Great Crusade to reunite humanity, he was impressed by everything Guilliman had accomplished.

The Emperor named Guilliman the primarch of the Ultramarines Legion, the largest and most successful of the Space Marine Legions. Guilliman’s strategic brilliance, coupled with his ability to inspire loyalty and lead by example, made him one of the most respected primarchs among his brothers.

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Key Takeaways:

  • Superhuman primarch who leads the Ultramarines Space Marine Legion
  • Brilliant strategist, statesman, and empire-builder
  • Mortally wounded by Fulgrim, then resurrected in the 41st millennium
  • Now Lord Commander of the Imperium and Imperial Regent in the Emperor’s name
  • Author of the Codex Astartes, the guide for Space Marine organization and tactics

The Great Crusade

As part of the Great Crusade, Guilliman led the Ultramarines in the conquest of vast swathes of the galaxy in the Emperor’s name. Whenever the Ultramarines brought a world into Imperial Compliance, Guilliman ensured it could defend and sustain itself before moving on.

This minimized casualties and left compliant worlds thriving and as productive members of the Imperium. Under Guilliman’s leadership, the Ultramarines grew to be the most numerous of the Space Marine Legions.

When the Emperor named Horus as Warmaster, Guilliman was among his staunchest supporters.

Guilliman’s approach to conquering and integrating worlds into the Imperium was methodical and efficient. He emphasized the importance of building infrastructure, establishing trade routes, and creating a stable system of governance.

This not only made the worlds he conquered more valuable to the Imperium but also ensured that they would remain loyal even in the face of adversity. Guilliman’s strategic acumen extended beyond the battlefield, and his ability to build and maintain an empire was unparalleled among the primarchs.

The Horus Heresy

When the Horus Heresy erupted and half the Space Marine Legions turned traitor, the Ultramarines were beset by the Word Bearers Legion at the Battle of Calth.

Despite being caught by surprise and suffering heavy losses, Guilliman rallied his forces and achieved victory, swearing to slay the Word Bearers primarch Lorgar for his treachery.

The Shadow Crusade saw Guilliman battle the Traitor forces of Lorgar and Angron across Ultramar. At the Battle of Nuceria, Guilliman defeated Lorgar but was laid low by Angron before Ultramarines were able to retrieve him.

Separated from the rest of the Imperium by warp storms, Guilliman established Imperium Secundus as a haven for Loyalist forces.

There Guilliman declared Sanguinius its regent and worked to keep the ideals of the Emperor alive. However, Guilliman frequently clashed with Lion El’Jonson over matters of policy.

After the warp storms abated, Guilliman led his Ultramarines on a grinding advance towards Terra, battling traitor forces every step of the way.

The long and grueling campaign took its toll on the Ultramarines, but Guilliman’s leadership and tactical brilliance ensured that they remained a cohesive and effective fighting force.


In the aftermath of the Heresy, Guilliman assumed the mantle of Lord Commander of the Imperium and, for a time, acted as the first lord of the Imperium’s High Lords of Terra.

Guilliman reorganized the Imperium’s military forces and authored the Codex Astartes, which broke down the Space Marine Legions into smaller chapters.

The Codex Astartes also codified the tactics, organization, and beliefs of the Space Marines, ensuring that they would remain a unified force even as they were split into separate chapters.

Guilliman led the Ultramarines for another century until disaster struck – he was mortally wounded in battle with the Daemon Primarch Fulgrim of the Emperor’s Children Traitor Legion. Guilliman was placed in stasis at the moment of death, and his body was entombed on Macragge for the next ten thousand years.

During this time, the Ultramarines and their successors continued to follow the teachings of the Codex Astartes and venerated their fallen primarch as a paragon of the Space Marine ideal.

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Return and Indomitus Crusade

In the closing days of the 41st Millennium, the Tech-Priest Belisarius Cawl was able to resurrect Guilliman from his mortal wounds using an ancient suit of power armor and Eldar technology.

Guilliman swiftly drove Chaos forces from Macragge and attempted to reach Terra through the Maelstrom, suffering betrayal from within and without.

Finally reaching the Throneworld itself, Guilliman became disgusted by the decay and superstition that had taken hold of the Imperium. After a tense confrontation with the Emperor himself, Guilliman declared himself Lord Commander of the Imperium and Imperial Regent, the living voice of the Emperor.

Guilliman next launched the Indomitus Crusade to stabilize the Imperium and push back the forces of Chaos. The century-long campaign saw him utilize Belisarius Cawl’s new Primaris Space Marines, turning the tide in embattled sectors across the galaxy before finally ending at the Battle of Raukos.

The Indomitus Crusade was a massive undertaking, involving millions of Imperial soldiers and thousands of ships. Guilliman’s strategic brilliance and inspirational leadership were crucial to its success, as he coordinated the efforts of the Imperial forces across the vast reaches of the galaxy.

Ultramarine Symbol

The Plague Wars

Afterward, Guilliman rushed back to Ultramar, where his realm was under assault by the Nurgle-corrupted forces of the Death Guard led by his brother Mortarion. Across a series of grueling campaigns, Guilliman used his tactical genius to outmaneuver the forces of Nurgle, striking deep into the corrupted Scourge Stars.

A final confrontation between Guilliman and Mortarion on Iax saw the Lord Commander seemingly slain by a poisoned sword, but through a miracle of the Emperor, Guilliman was restored and drove off the Daemon Primarch.

With Ultramar safe for now, Guilliman now plans to venture into the Dark Imperium to shore up its defenses against the servants of Chaos.

The Plague Wars tested Guilliman’s resolve and strategic acumen to their limits. The forces of Nurgle were relentless and seemingly endless, and the corruption they spread threatened to engulf all of Ultramar.

However, Guilliman’s faith in the Emperor and his own abilities never wavered, and he led the Imperial forces to victory against impossible odds.

His confrontation with Mortarion was a battle of both physical and spiritual strength, and his ultimate triumph served as a powerful reminder of the might of the Imperium and the indomitable will of its greatest champions.

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The Codex Astartes and Guilliman’s Legacy

One of Guilliman’s most enduring legacies is the Codex Astartes, the comprehensive guide to Space Marine organization, tactics, and philosophy that he authored in the aftermath of the Horus Heresy.

The Codex Astartes has served as the foundation for the Space Marines for ten thousand years, ensuring that they remain a united and effective fighting force even as they are divided into countless chapters spread across the galaxy.

The Codex Astartes is more than just a military manual; it is a distillation of Guilliman’s strategic genius and his deep understanding of the role of the Space Marines in the Imperium.

It emphasizes the importance of flexibility, adaptability, and the use of combined arms tactics, while also stressing the need for discipline, loyalty, and unshakeable faith in the Emperor.

While some chapters, such as the Space Wolves and the Black Templars, have diverged from the strict dictates of the Codex Astartes, the vast majority of Space Marines adhere to its teachings and venerate Guilliman as a paragon of the Adeptus Astartes.

Even after his return, Guilliman continues to refine and update the Codex Astartes, ensuring that it remains relevant and effective in the face of the ever-changing threats to the Imperium.

Roboute Guilliman

(Image Credit: Calgar)


Guilliman is a towering superhuman warrior armed with potent weapons and armor:

The Emperor’s Sword: Blazing with psychic power, this legendary blade was once wielded by the Emperor himself in ages past. It is an incredibly powerful weapon, capable of cutting through even the toughest armor and smiting the mightiest of foes.

In Guilliman’s hands, it is a symbol of the Emperor’s authority and a reminder of the primarch’s duty to defend the Imperium.

Hand of Dominion: This mighty power fist not only enhances Guilliman’s already prodigious strength but also contains a built-in bolter, allowing him to deliver devastating ranged attacks while still engaging in melee combat.

The Hand of Dominion is a testament to Guilliman’s skill as a warrior and his ability to adapt to any situation on the battlefield.

Armor of Fate: A unique suit of power armor that sustains Guilliman’s life and heals any wound. This ancient and powerful artifact was crafted specifically for Guilliman by Belisarius Cawl, using a combination of cutting-edge Imperial technology and mysterious Eldar techniques.

The Armor of Fate not only protects Guilliman from harm but also enhances his already superhuman abilities, making him an even more formidable force on the battlefield.

Frequently Asked Questions

What is Roboute Guilliman’s role in the Imperium?

Roboute Guilliman is the Primarch of the Ultramarines Space Marine Legion and the current Lord Commander of the Imperium and Imperial Regent.

He is the living voice of the Emperor and is responsible for leading the Imperium’s military forces and ensuring the survival and prosperity of humanity.

How was Guilliman able to return after being mortally wounded by Fulgrim?

Guilliman was resurrected by the efforts of the Tech-Priest Belisarius Cawl, who used a combination of advanced Imperial technology and Eldar techniques to heal his wounds and bring him back to life.

The exact details of the process are not fully understood, but it is believed that the Emperor himself may have had a hand in Guilliman’s resurrection.

What is the Codex Astartes, and why is it so important?

The Codex Astartes is a comprehensive guide to Space Marine organization, tactics, and philosophy authored by Roboute Guilliman in the aftermath of the Horus Heresy. It serves as the foundation for the modern Space Marine Chapters and ensures that they remain a united and effective fighting force despite being spread across the galaxy.

The Codex Astartes is venerated by most Space Marines as a sacred text and a testament to Guilliman’s strategic genius.

How does Guilliman feel about the current state of the Imperium?

Upon his return, Guilliman was horrified by the decay, superstition, and corruption that had taken hold of the Imperium in his absence. He sees it as his duty to restore the Imperium to its former glory and to lead humanity out of the darkness and into a new golden age.

However, he also recognizes that the task before him is immense and that it will take all of his skill, determination, and faith in the Emperor to succeed.

What is Guilliman’s relationship with his brother primarchs?

Guilliman’s relationships with his brother primarchs are complex and varied. He was close friends with some, such as Sanguinius and Rogal Dorn, while he had more difficult relationships with others, such as Lorgar and Angron.

Since his return, Guilliman has had to confront the fact that many of his brothers have either fallen to Chaos or been lost to history, and he feels a deep sense of responsibility to carry on their legacy and to honor their sacrifices in the name of the Emperor.



Roboute Guilliman is a key figure in Warhammer 40k and one of the most powerful individuals in the galaxy.

His genius in both warfare and statesmanship is unmatched, and he embodies all the greatest ideals of the Imperium – bravery, honor, loyalty, and self-sacrifice.

His return has brought new hope to an Imperium beset by countless threats, and his leadership and strategic brilliance have already proven invaluable in the fight against the forces of Chaos.

As the Lord Commander of the Imperium and the Imperial Regent, Guilliman faces the daunting task of restoring the Imperium to its former glory and leading humanity out of the darkness and into a new golden age. It is a task that will test his every skill and require all of his strength, determination, and faith in the Emperor.

But if anyone is capable of succeeding in this monumental endeavor, it is Roboute Guilliman, the Avenging Son and the greatest of the Emperor’s primarchs.

Wish to learn more about Roboute? Head on over to the official wiki!

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