Ullanor System

The Ullanor System is the Ork capital well of the Ullanor Sector in Segmentum Solar, the stage for the Emperor's Triumph and later the War of the Beast. Horus broke Urlakk Urg here; the Emperor named him Warmaster on the same dust.

The Beast turned the planet into Gorkogrod. Vulkan died fighting there. The Mechanicus secretly teleported the world rather than burn it; later maps treat that relocated mass as Armageddon. This overlay keeps the Ullanor pin and the Armageddon pin as separate ids.

The Ullanor System still matters as the triumph that created a Warmaster and the later green capital the Imperium tried to steal. Unofficial fan summaries keep the Ullanor Sector parent and do not delete the system just because Armageddon inherited a rumour.