Maris is a remote Imperial World in the Nimerian subsector, a frontier district with little contact with central authorities. Classified as an agricultural world. Overexploited and is undergoing desertification. Has long had trouble meeting its tithe - and is therefore content to stay under the Imperium’s auspex. It is worthy of mention since it is the first major attack upon an Imperial world by Castor the Great.

The Broken Chains pretends to carry an Inquisitor in trouble. While Maris’ leaders gather upon the orbiting battlestation and its finest regiments muster at the central spaceport, Castor strikes suddenly and with great force. In the ensuing chaos the reavers are able to eliminate the political leadership, military command and control, orbital defences, and many PDF formations. The planet's capital is assaulted, sacked, and sacrified to the glory of the Four.