Inwit Cluster

The Inwit Cluster, or Inwit System, is a group of closely packed ice worlds in Segmentum Tempestus from which Rogal Dorn ruled a small empire. Its principal world, Inwit, comprises hive-caverns beneath kilometres of ice, nomad clans, and shipyards that later sources describe as comparable in scale to Jupiter.

Dorn governed the cluster before the Emperor found him. After his departure, the Imperial Fists continued to recruit from its worlds. During the Horus Heresy, Horus’s forces spent four years attempting to subdue the cluster. A traitor fleet led by the Emperor’s Children burned a number of its worlds before the Siege of Terra drew the traitors away. The Feast of Blades occasionally returns to the cluster.

The Inwit Cluster remains notable as Dorn’s second seat of rule alongside Terra. On this site’s unofficial maps, it is placed under Segmentum Tempestus at sector level, reflecting that it is a group of worlds rather than a single planet.