Compliance of Kharaatan
The Compliance of Kharaatan (or Khar-tann City) was a battle of the Great Crusade. Waged by the Salamanders and Night Lords, led by their respective Primarchs Vulkan and Konrad Curze, on the world of Kharaatan against Humans worshipping a coven of Eldar Psykers, Curze oversaw many atrocities against civilian populations during the war to create terror.
After the Night Lords massacred the population of an entire city, he came into conflict with Vulkan, who reported him to Warmaster Horus and Rogal Dorn. However, Curze's terror campaign proved successful, and resistance collapsed bloodlessly shortly after. After the campaign, the surviving population was herded into camps designated for Xenos collaborators vs. non-collaborator. The Imperials also captured the Eldar Witches, who soon escaped and caused havoc. During the mayhem a stray Night Lords bullet killed the Remembrancer Seriph, driving Vulkan into a rage that caused him to murder a surrendering Eldar child. As Curze gloated over the vox, the incident haunted Vulkan deeply.