Military action
The Exiled Lord Imaru Baraqu chose to start by cleansing the largest and most ancient hive-city on the planet of Raakata Primus, which was at the time controlled by the brutal xenos Slavers. The Exiled Legion prosecuted a long and bloody campaign. The vile aliens wasted no opportunity to use forbidden xenos weapons and profane tactics to remain in power. Despite this, none could stand against the might of the Exiles, and soon the liberated human slaves of the hive city were swearing eternal fealty to the Emperor of Mankind.