Signus Prime

Signus Prime was the capital of a seven-world industrial cluster until daemons turned it into a domain of Kyriss and Ka’Bandha.

Horus dispatched the Blood Angels to the cluster with the intention that the Legion should be destroyed there. Sanguinius extracted the Legion and afterwards declared the entire cluster dead in perpetuity. A cyclonic charge later destroyed the Cathedral of the Mark.

Beacons continue to warn traffic away from the cluster. Its standing remains that assigned by Sanguinius: a group of seven worlds formally regarded as dead.