
By the closing centuries of the 30th Millennium, worlds brought into the fold of the Imperium of Man—whether through conquest, persuasion, or voluntary allegiance—were said to have achieved what was known as "Imperial Compliance."
Sometimes, integration was achieved through diplomacy, with promises of unity, progress, and a return to Humanity’s former glory among the stars. Yet far more often, such outcomes required military dominance. Many planetary rulers, long independent and accustomed to absolute authority over their domains, resisted the Imperium's reach. In countless cases, force was the only means by which submission could be ensured. These military operations saw tyrants overthrown, sorcerers and psykers exterminated, and entire populations purged of xenos, mutants, and Warp-spawned abominations. Over time, these efforts came to be known not merely as wars of conquest, but as Compliance campaigns—an enduring term for the act of bringing a world under Imperial rule.