Segmentum Pacificus

Segmentum Pacificus is one of the five major divisions of the Imperium, lying in the west and having its fortress at Hydraphur. It is chiefly associated with two episodes: the Macharian Crusade and the Night of a Thousand Rebellions.

The Sabbat Worlds, Macharia, Colchis and the site of the later war at Leviathan’s Sanctum all lie within the Segmentum. Nova Terra once claimed authority over the whole of it. The Macharian Crusade annexed a portion of the region, but that portion was not retained after the Heresy.

Segmentum Pacificus remains significant as the western bulwark of Terra. It is treated here as a distinct Segmentum and not as a composite with Segmentum Tempestus.