Segmentum Obscurus

Segmentum Obscurus is the great northern division of the Imperium, a vast and troubled region forever darkened by the presence of the Eye of Terror that festers within its bounds. More than any other segmentum, it lives under the perpetual shadow of Chaos, and its history is written in the blood of endless war.

For ten thousand years the worlds of Obscurus have stood as the first line of defense against the horrors pouring from the great warp rift. The fortress world of Cadia guarded the only stable passage from the Eye for millennia, and generation upon generation of the Astra Militarum gave their lives to hold that line against the Black Crusades of the Chaos Space Marines. When Cadia at last fell, the Great Rift tore open and the segmentum was riven asunder.

Despite these calamities, Segmentum Obscurus endures. Its people are hardened by ceaseless conflict, its regiments among the most battle-tested in the Imperium. It is a grim and watchful land, the northern rampart of Mankind, where the war against damnation has never once paused in all the long millennia of the Imperium's decline.