Ullanor is the ork world where Horus Lupercal earned the title Warmaster, and it’s the same planet humanity later calls Armageddon. Its story runs from the Great Crusade through the Horus Heresy to the War of the Beast, making it one of the most fought-over worlds in the galaxy.
What ullanor is
Ullanor Prime sits in the Ullanor Sector, at the heart of the Ullanor System. Long before humans reached it, a Necron construct called Artifact XE3-36 was entombed near its equator, possibly as early as 560,000 BC.
By M31 the planet was the centre of a vast ork empire led by Warboss Urlakk Urg. When Imperial forces broke that empire during the Ullanor Crusade, the world’s fate changed forever. It’s since become known as Armageddon.
The ullanor crusade and triumph
Horus Lupercal commanded the Imperial forces that crushed Urlakk Urg’s orks, and that victory earned him the title Warmaster. The Emperor then ordered the Adeptus Mechanicus to reshape the planet, turning it into the stage for the Ullanor Triumph, the most famous parade in Imperial history.
That triumph wasn’t just ceremony. It marked the moment Horus was publicly elevated above his brothers, and it’s the event later traitors deliberately echoed when they gathered on the same world before striking for Terra.
Horus heresy and the war of the beast
After the Battle of Beta-Garmon, Horus ordered his forces to muster at Ullanor before the push on Terra. Fulgrim, Perturabo, Angron, Magnus, Alpharius, and Lorgar arrived with their fleets, along with scattered Night Lords. They held a dark mirror of the old Triumph, then each fleet sacrificed a tenth of its slaves to the Chaos Gods for safe passage through the Warp.
About 1,500 years later, a colossal ork Warboss known only as The Beast rose on Ullanor and made it the centre of a new empire. The world was urbanised almost entirely, and The Beast built a temple-Gargant at the exact spot where the Emperor and Primarchs had stood. He used Ullanor as the template for his Attack Moon concept, converting the planet itself into a battlestation meant to destroy Terra.
Vulkan led a second Imperial invasion to kill The Beast. It was bitter urban warfare, not the open battles of the first crusade. Vulkan eventually took a strike force into Gorkogrod’s temple-Gargant and duelled The Beast directly. He seemed to sacrifice himself to win, and ork resistance crumbled, though greenskins endured on the world and a third invasion followed.
Why ullanor matters
Ullanor is a hinge in Imperial history. It’s where Horus became Warmaster, where the Heresy’s final muster began, and where the orks came closer to destroying Terra than almost anyone else.
It’s also the same world as Armageddon, which means every later war fought there sits on top of this older history. The planet’s record is a reminder that humanity’s greatest triumph and its worst betrayal happened on the same soil.
Key facts
- Ullanor Prime is the world later called Armageddon.
- Horus Lupercal became Warmaster after defeating Warboss Urlakk Urg there.
- The Emperor held the Ullanor Triumph on the planet after the crusade.
- Traitor forces mustered at Ullanor before the push on Terra during the Heresy.
- The Beast rose on Ullanor about 1,500 years later and turned it into a battlestation.
- Vulkan led a second invasion to kill The Beast in the temple-Gargant of Gorkogrod.
FAQ
Is Ullanor the same as Armageddon?
Yes. Ullanor Prime is the world later known as Armageddon. The name changed over time, but it’s the same planet in the Ullanor System.
Who was the Warboss at Ullanor during the Great Crusade?
Urlakk Urg led the ork empire that Horus Lupercal defeated during the Ullanor Crusade.
What happened at Ullanor during the Horus Heresy?
Horus ordered his traitor forces to muster there before the drive on Terra. The Primarchs held a dark version of the Ullanor Triumph and sacrificed slaves to the Chaos Gods for safe Warp passage.