Dulan lies within the Damocles Gulf, that troubled region on the Imperium's eastern fringe where the young and hungry Tau Empire pressed against the boundaries of Mankind's domain. During the Damocles Crusade, launched to check the xenos expansion, Dulan became one of the many worlds contested between the Emperor's forces and the alien invaders who offered its people the seductive lie of the Greater Good.
The fighting on Dulan was fierce, for the Tau had entrenched themselves well and the Astra Militarum regiments of the crusade faced not only the enemy's superior firepower but the treachery of a populace swayed by xenos promises. The world's ruling caste had thrown in their lot with the Tau, and rooting them out demanded blood and fire in measure. The name of Dulan is remembered for the death of a Tau commander whose fall marked a bitter turn in the campaign.
Though the Damocles Crusade ultimately withdrew, unable to press the war to its conclusion, worlds like Dulan remained scarred by the conflict, their loyalties fractured between the Imperial Creed and the alien creed of unity. It stands as a reminder that the frontier of the Imperium is not merely a line of battle but a war of ideas, where the enemy conquers minds as readily as territory, and even a single world may become the seed of a wider betrayal.