What are the Ultramarines? Conquering the Galaxy with Legendary Honor, Courage, and Unwavering Loyalty in the 40k Millennium

Ultramarine Symbol

What are the Ultramarines? The Legendary Space Marine Chapter Explained

The Ultramarines are one of the most famous and well-respected Space Marine Chapters in the Warhammer 40,000 universe. As a passionate hobbyist who has loved the lore and miniatures of Warhammer 40k for over two decades, I’ve always been fascinated by the noble warriors in blue and gold. In this some what long guide, I’ll delve into the history, culture, organization, and notable characters of the Ultramarines Chapter. However if you are still looking for more Information I would suggesT the Wikilink at the end!

Whether you’re a veteran fan of Warhammer 40k or new to the setting, lets set sail on this exploration of the sons of Guilliman, the legendary Primarch of the Ultramarines.

Want to learn more about Space Marines? Read here for What Are Space Marines? 

What are the Ultramarines?: Origins and History

The Ultramarines were originally the XIII Legion of the twenty Space Marine Legions created to fight in the Emperor’s galaxy-spanning Great Crusade in the late 30th millennium. Recruited from a variety of warlike cultures on Terra, the XIII Legion quickly distinguished itself as a disciplined, flexible force able to fight effectively in any theater of war.

Everything changed when their lost Primarch, Roboute Guilliman, was rediscovered on the world of Macragge. Under Guilliman’s leadership, the XIII Legion was reforged into the Ultramarines, and Macragge and the surrounding systems became Ultramar, a shining beacon of order and civilization modeled on Guilliman’s visions.

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What are the Ultramarines

What are the Ultramarines?: The Horus Heresy

When Warmaster Horus and half the Space Marine Legions turned traitor, the Ultramarines were among the hardest hit of the Loyalist forces. Caught by surprise and savaged by the Word Bearers Legion at the Battle of Calth, the Ultramarines were unable to arrive at Terra in time to assist the Emperor during the Siege.

However, in the dark days after the Heresy, Guilliman kept hope alive by creating the Imperium Secundus as a failsafe empire, and then helping stabilize the Imperium in the aftermath of the Emperor’s internment on the Golden Throne. His greatest work was the Codex Astartes, which divided the Legions into smaller, more manageable Chapters to prevent any one man from wielding the power of an entire Legion again.

What are the Ultramarines?: 10,000 Years of War

For the next ten millennia, the Ultramarines would become a byword for courage and honor, their strict adherence to the Codex Astartes setting the standard that all other Space Marine Chapters would be judged by. From their fortress-monastery on Macragge, the Chapter and its many successors would sally forth time and again to push back the hordes of Chaos, xenos, and Traitors assailing the worlds of the Imperium.

Some of the Ultramarines’ most legendary battles during this time include:

  • The Battle of Macragge against Hive Fleet Behemoth, the first Tyranid invasion of the Imperium
  • The Corinth Crusade to liberate a hundred worlds from the grip of the Orks
  • The Damnos Incident against the awakening Necrons
  • The Assault on Black Reach where the 2nd Company under Captain Cato Sicarius defeated the Orks of Waaagh! Zanzag

No matter the foe, the sons of Guilliman would always live up to their Primarch’s words: “Courage and honor!”

What are the Ultramarines?: The Return of Guilliman

In the late 41st Millennium, with the Imperium beset by foes on all sides and crumbling under the weight of bureaucracy and superstition, an ancient secret on the Ultramarines’ homeworld of Macragge was unearthed. For ten thousand years, Roboute Guilliman had sat in stasis at the heart of the Fortress of Hera, frozen in time since his mortal wounding during the Battle of Thessala against his traitor brother Fulgrim.

Now, as the 13th Black Crusade unleashed the forces of Chaos across the galaxy as never before, the ancient Archmagos Belisarius Cawl and his mysterious Aeldari allies worked desperately to revive the Primarch. With Guilliman’s tactical genius, the Chaos invasion of Ultramar was repelled.

Gathering a coalition of Imperial forces including his resurrected Primaris Space Marines, Guilliman launched the Indomitus Crusade to stabilize the Imperium even as a great tear in reality, the Cicatrix Maledictum, split the galaxy in half. After a hundred years of crusading, Guilliman finally arrived on Terra and assumed the mantle of Lord Commander of the Imperium, determined to shepherd humanity back from the brink.

Back in Ultramar, the returned Primarch set about preparing his Chapter and his realm for the greatest trials yet to come in the grim darkness of the far future…

What are the Ultramarines?: Organization and Culture

The Ultramarines Chapter is strictly divided along the guidelines laid out in Roboute Guilliman’s Codex Astartes. There are 10 Companies, each made up of up to 100 Space Marines. Unlike other Chapters, the Ultramarines maintain a much larger pool of Scouts, and are unique in having a dedicated Fleet Command.

Each Company is led by a Captain, who serves as both a battlefield commander and a Master of some aspect of the Chapter’s operations. For example, the Captain of the 2nd Company is traditionally the Master of the Watch, responsible for the defense of Macragge.

All answer to the Lord Macragge, the title of the Chapter Master – an office currently held by the legendary hero Marneus Calgar.

The Ultramarines rule over the Five Hundred Worlds of Ultramar as benevolent masters, in contrast to the often draconian governance of other Imperial worlds.

As a result, they maintain close ties to the Ultramarian Planetary Defense Forces and other mortal institutions. The culture of Ultramar, with its focus on learning, justice, and discipline, is heavily shaped by the Ultramarines in turn.

In battle, the Ultramarines favor a combined-arms approach that plays to their strengths as an extremely flexible, well-rounded force. Guilliman taught that every battle is a synthesis of carefully structured planning (The Theoretical) and the need to adapt to developing circumstances on the fly (The Practical).

Where other Chapters over-specialize, the Ultramarines are the ultimate generalists, able to effectively respond to any tactical situation.

What are the Ultramarines?: Notable Characters

Many legendary heroes have served in the Ultramarines over the millennia. A few of the most famous include:

  • Roboute Guilliman – The Ultramarines Primarch and author of the Codex Astartes, now returned to lead the Imperium.
  • Marneus Calgar – The Lord Macragge and current Chapter Master, a legendary general and warrior.
  • Chief Librarian Tigurius – The most powerful psyker in the Imperium, able to divine the future.
  • Chaplain Cassius – The Ultramarines’ Master of Sanctity, famed for his hatred of Tyranids.
  • Captain Cato Sicarius – The pride of the 2nd Company, a skilled but arrogant officer.
  • Sergeant Telion – A legendary Scout Sergeant and peerless marksman.
  • Captain Uriel Ventris – Current commander of the 4th Company, exiled and redeemed.

What are the Ultramarines?: Wargear and Relics

The Ultramarines have an extensive arsenal of powerful relic weapons and wargear, including the Primarch’s own blade, the Emperor’s Sword, the Gauntlets of Ultramar worn by Calgar, master-crafted artificer armour, and ancient plasma weapons able to cut through the heaviest enemy armor.

In addition to their many Pursuit Squads geared for rapid strikes and the Tyrannic War Veterans who have battled the Tyranids time and again, the Ultramarines also have access to powerful superheavy tanks like the Astraeus and Fellblade, as well as a mighty fleet of battle barges and strike cruisers led by Guilliman’s flagship, the ancient Macragge’s Honour.

What are the Ultramarines?: Notable Successor Chapters

Countless Space Marine Chapters trace their lineage to Roboute Guilliman and his Legion. A few of the most famous Ultramarines successors include:

  • The Novamarines, stalwart defenders of the Eastern Fringe
  • The Sons of Guilliman, unshakeable guardians of the Galahad sector
  • The savage Mortifactors of Posul, a grim Death World
  • The Genesis Chapter, known for their diplomatic skill
  • The fleet-based Aurora Chapter, masters of void warfare
  • The Silver Eagles, dedicated to cleansing Necron Tomb Worlds

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What are the Ultramarines?: The Indomitus Crusade and Beyond

As one of the greatest Space Marine Chapters and a key player in the Indomitus Crusade, the Ultramarines continue to fight at the forefront of humanity’s war for survival in the 41st Millennium. With Guilliman awakened and the introduction of Primaris Marines using his perfected gene-seed, a new age of heroism has dawned for the sons of Ultramar.

If you are looking for a more detailed overview of the Ultramarine, we recommend the wiki page!

Whether battling the surging tides of Tyranids, the implacable advance of Necrons, or the festering forces of Chaos, the Ultramarines will continue to hold the line against the encroaching darkness. For courage and honor!

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