|Outcome||Decisive Imperial Victory|
| Emperor of Mankind
Warmaster Horus Lupercal
Primarch Roboute Guilliman
Primarch Jaghatai Khan
First Captain Ezekyle Abaddon
|Warboss Urrlak Urruk(KIA)|
| 100,000 Space Marines from the Luna Wolves, Ultramarines, and White Scars
8 million Imperial Army troops
100 Legio Mortis Titans
600 Imperial Armada warships
|Millions of Orks|
The Ullanor Crusade was a vast assault upon the powerful empire of Ork Overlord Urlakk Urg during the Great Crusade in 000.M31. It is remembered as Horus's greatest victory while he was still loyal to the Emperor and the act that earned him the title of Warmaster. It was the last battle of the Crusade where the Emperor personally led his forces.
Assault on Ullanor
While the Ultramarines and White Scars Space Marine Legions, supported by newly-raised Imperial Army regiments, were tasked to retake the outlying planets of the Ullanor system, the Luna Wolves under Horus had their fleet drove straight for the central world. The force was massive: one hundred thousand Space Marines, eight million Imperial Army troops, and hundreds of spacecraft.
Employing his favoured tactic of a direct strike at the enemy command structure, Horus unleashed his Legion. Drop pods crashed to the ground all around Urg's fortress-palace. Heavy shuttles deployed Land Raiders and Predators and armoured Space Marines advanced on the defences. Then, as hundreds of orks rushed to join the battle on the perimeter walls, Horus and a Terminator detachment teleported directly to the foot of the great central tower. As the Luna Wolves blasted away the guards, mobs from the walls raced back to protect Urg. Horus took ten of his Terminators up the tower, leaving the rest to hold back the orks.
At the pinnacle of the tower, they found Urg in a grand chamber accompanied by forty of the biggest orks in his empire. Horus charged straight toward the warlord, slicing through muscled green bodies with his lightning claws. The Terminators with him similarly crashed into combat. Slowly, they hacked a path through the mob until Horus faced Urg himself. The enormous Overlord was simply no match for the Primarch's skill and unnatural power. Horus crippled his enemy, hefted Urg's broken body out onto the roof, and threw him screaming from the battlements to fall far below, amongst the horde of orks still assaulting the lower levels.
The sudden demise of their mighty leader sent a panic through the Greenskin forces, which fell back from the Terminators into the advancing Luna Wolves and were slaughtered. Back in the Overlord's chamber. Horus found his First Captain Ezekyle Abaddon standing alone and gore-drenched amongst the crushed and broken bodies of the Justaerin and the orks. As word of his death spread, the Overlord's empire fragmented. The Imperial forces retook control of the quadrant within a year. Naturally, the Luna Wolves claimed to have liberated substantially more worlds than their allies.
The Ullanor Triumph
Not long after what had become perhaps the greatest victory of the Crusade, the Emperor of Mankind declared that a great Triumph on Ullanor would be held to recognize the glory of the Crusade.
Preparation for the Triumph took a considerable effort, with the Adeptus Mechanicus utilizing massive geoformer engines and millions of Servitors, prisoner-slaves, and Thralls to flatten an entire continent and lay down a massive mirror-smooth granite path that was 5 kilometers wide and 500 kilometers long. Serving as the Triumph's primary parade ground, it was decorated along its entire length with Ork skulls slain in the battle. At the end of the path, a citadel was constructed upon a mountaintop that held the Emperor, Horus, Sanguinius, Mortarion, Magnus, Angron, Jaghatai Khan, Lorgar, Rogal Dorn, Fulgrim, Malcador, and Constantin Valdor as well as many other members of the Council of Terra and Imperial nobility. The citadel was guarded by a sizable Custodes and Sisters of Silence detachment and two gold-plated Warlord Class Titans.
During the Triumph eight million Imperial Army soldiers and thousands of armored vehicles marched along the Granite path in parade formation. After them came hundreds of Titans from the Collegia Titanica. Then came fourteen Space Marine Legions from the Luna Wolves, Blood Angels, Death Guard, Thousand Sons, World Eaters, White Scars, Word Bearers, Imperial Fists, Emperor's Children, Raven Guard, Salamanders, Ultramarines, Iron Hands, and Dark Angels. Thousands of Imperial Armada aircraft clouded the sky, and Horus was presented as the grand finale of the Triumph. Shocking all present, the Emperor then announced Horus as Warmaster of the Great Crusade and that the Luna Wolves would now be known as the Sons of Horus. He also announced his retirement from the Great Crusade, expecting that the Imperial forces would obey Horus's commands from then on as if they were his own.
After the Ullanor Crusade, the Imperium believed that the ork race had been broken and could not present a credible threat again. Though scattered groups of orks would periodically attack the Imperium's frontier, they were regarded as little more than troublesome pests. This complacency would be suddenly and terribly reversed in M32, when the War of the Beast brought the orks to Terra itself and decimated the Imperium's entire military.
The Triumph of Ullanor resembles the great Roman Triumph of Julius Caesar following his rise to absolute power and the defeat of his rivals. Like Caesar's, the Triumph at Ullanor represented the peak of the Emperor's power and glory shortly before catastrophe beset his empire. For Caesar this was his assassination and the civil wars that followed. For the Emperor, this would be the Horus Heresy and his internment to the Golden Throne.
- 1: Index Astartes: Black Legion
- 2: False Gods (Novel) by Graham McNeill, Chapter Five
- 3: Fear to Tread (Novel) by James Swallow, Interlude: Ullanor
- 4: A Thousand Sons (Novel), by Graham McNeill, Chapter 15
- 5: The Horus Heresy Book Three, pg. 19
- 6: I Am Slaughter (Novel) by Dan Abnett, Chapter 30
- 7: Echoes of the Long War (Novel) by David Guymer, Chapter 7
- 8: The Beast Must Die (Novel) by Gav Thorpe, [Needs Citation]