Cadian System

The Cadian System is the star system of the Cadian Gate, the only fleet-scale corridor out of the Eye of Terror, in Segmentum Obscurus. It lies in the Cadian Sub-sector of the Cadian Sector. Cadia, the fortress world of the system, gave its name to both the system and the Gate. For ten millennia Imperial warfleets used the corridor to hold the Eye closed, while Cadia’s pylons kept the local warp quiet enough for a fleet to pass.

When the pylons failed during the 13th Black Crusade, the warp storm Baphomael expanded to the edge of the system and Cadia broke apart. Other worlds in the system engaged the remaining Chaos spearhead, and the Great Exodus moved Imperial defences from the failing fortress to those surviving worlds. The kasrs, forge-moons, and penal stations around the Gate, previously rear areas for Cadian-born regiments, became the front line.

Cadia is now a shattered remnant. Iron Warriors later seized it from a Black Legion garrison. The Cadian System nonetheless retains its importance as the site of the Gate, although the planet that gave it its name no longer exists as a world. The corridor remains the only fleet-scale route out of the Eye of Terror, and the Imperium continues to contest the system rather than abandon it.