Roboute Guilliman is the Primarch of the Ultramarines and the Emperor’s own genetic son, a warlord who’d rather build a civilisation than just burn one down. He wrote the Codex Astartes, held the Imperium together after the Horus Heresy, and after ten thousand years in stasis he’s back, running the show as Lord Commander and Imperial Regent.
Who is Roboute Guilliman?
Guilliman is one of the twenty Primarchs, gene-forged sons of the Emperor scattered across the galaxy as infants. He landed on Macragge in Ultramar and was raised by Konor Guilliman and Tarasha Euten, eventually ruling the world as its sole consul.
What set him apart from his brothers was his outlook. He saw himself as a builder of civilisations as much as a conqueror, and he ran his own small empire before the Emperor ever found him.
He’s also known by a pile of titles: the Avenging Son, the Victorious, Master of Ultramar, Blade of Unity, and Uniter. These days he adds Lord Commander of the Imperium and Lord Regent to the list.
The Great Crusade and the Horus Heresy
During the Great Crusade, Guilliman led the XIII Legion, the Ultramarines, one of the largest and most organised Space Marine Legions. He was as much a statesman as a general, and his realm of Ultramar became a model of efficient, prosperous Imperial rule.
When Horus turned traitor, Guilliman was cut off from Terra by the Ruinstorm and couldn’t reach the Emperor in time. In that isolation he helped set up Imperium Secundus, a short-lived contingency state, before the truth of the Heresy caught up with him. He arrived too late to fight at the Siege of Terra.
After the Heresy: rebuilding and the Codex
With the Emperor entombed on the Golden Throne and the Imperium in ruins, Guilliman took charge as Lord Commander. His biggest legacy is the Codex Astartes, the tactical and organisational doctrine that broke the Legions into Chapters and shaped the modern Imperial military.
That reform wasn’t popular with everyone. Some of his brothers saw it as a power grab, and it set the template for how Space Marines have been organised ever since.
The return of the Avenging Son
Guilliman was gravely wounded by the daemon primarch Fulgrim and spent roughly ten thousand years in a stasis field on Macragge, hovering between life and death. He was revived shortly after the Thirteenth Black Crusade, thanks in part to the Eldar and the tech-priests of Mars.
Since waking, he’s led the Indomitus Crusade, launched the Primaris Space Marines, and taken up the roles of Lord Commander and Imperial Regent. In effect, he speaks for the Emperor and runs the Imperium day to day.
Key facts
- Roboute Guilliman is the Primarch of the Ultramarines and a genetic son of the Emperor.
- He wrote the Codex Astartes, reshaping the Imperium’s military after the Horus Heresy.
- He ruled Ultramar as its Master before and after the Emperor found him.
- Fulgrim wounded him, leaving him in stasis for roughly ten thousand years.
- He returned during the Era Indomitus as Lord Commander and Imperial Regent.
FAQ
Is Roboute Guilliman still alive in Warhammer 40k?
Yes. He was mortally wounded by Fulgrim and kept in stasis for about ten thousand years, but he was revived in the Era Indomitus and now leads the Imperium as Lord Commander and Regent.
What is the Codex Astartes?
It’s the military doctrine Guilliman wrote after the Horus Heresy. It broke the old Space Marine Legions into smaller Chapters and laid out how the modern Imperial military is organised.
Which Legion does Guilliman command?
The Ultramarines, the XIII Legion. He’s their Primarch, and they’re his genetic sons.