Segmentum Pacificus is one of the five Segmentums that divide the Imperium’s galaxy, a vast western region run from the fortress world of Hydraphur. It’s been a trouble spot for millennia, from the Nova Terra Interregnum to the Night of a Thousand Rebellions and the coming of Hive Fleet Leviathan.
What Segmentum Pacificus is
The Imperium splits its territory into five Segmentums. Pacificus is the western one, and its Segmentum Fortress sits at Hydraphur, governed by the Lords of Hydraphur.
It borders Segmentum Solar to the galactic east, Obscurus to the north east, Ultima to the far east, and Tempestus to the south east. That puts it on the front lines of some of the Imperium’s oldest and newest crises.
Worlds worth knowing
Pacificus covers everything from shrine worlds to war zones. Some names come up again and again in the lore.
Nova Terra is the world that once broke away and ruled the whole Segmentum during the Nova Terra Interregnum. Colchis is the homeworld of the Word Bearers, one of the most consequential planets in Imperial history. Tanith is the lost home of the Tanith First and Only, and Verghast is its sister world in the Sabbat Worlds crusade.
Sanctum has become a rallying point in the current war against Hive Fleet Leviathan, with Lord Commander Solar Arcadian Leontus and Captain-General Trajann Valoris gathering forces there.
- Adrantis Five, Atar-Median, Macharia, Mortikah VII and Ultima Macharia are all named Pacificus worlds.
- Xana is a forge world known for its tech-heresy.
- The Halo Zone, the Seventh Blackstone Fortress and Precipice sit out in the dark reaches of the Segmentum.
A history of rebellion
Pacificus has a habit of going its own way. During the Nova Terra Interregnum, the Ur-Council of Nova Terra claimed the entire Segmentum for itself.
The Macharian Crusade later brought thousands of worlds back into the Imperial fold, but many were lost again in the Macharian Heresy that followed.
In 999.M41, mass uprisings known as the Night of a Thousand Rebellions swept across Pacificus. Darkhold, Minisotira and Enceladus were caught up in the chaos, and even the Lions Defiant Chapter had its homeworld hit by insurgents. Contact with much of the Segmentum has been shaky ever since.
The Tyranid threat
In M42, Hive Fleet Leviathan launched a huge offensive into Pacificus. The Imperium wasn’t ready for it.
Sanctum has become the focal point of the defence, with Leontus and Valoris pulling together whatever forces they can. It’s one of the biggest active war zones in the setting right now.
Key facts
- Segmentum Pacificus is one of the Imperium’s five Segmentums, covering the galactic west.
- Its Segmentum Fortress is Hydraphur, ruled by the Lords of Hydraphur.
- Nova Terra once ruled the whole Segmentum during the Nova Terra Interregnum.
- The Macharian Crusade reclaimed thousands of worlds, many lost again in the Macharian Heresy.
- In 999.M41 the Night of a Thousand Rebellions swept the region.
- Hive Fleet Leviathan invaded Pacificus in M42, with Sanctum as the main rallying point.
FAQ
Where is Segmentum Pacificus?
It’s the western Segmentum of the Imperium, with its fortress at Hydraphur. It borders Solar, Obscurus, Ultima and Tempestus.
What is the Night of a Thousand Rebellions?
A mass uprising across Pacificus in 999.M41. Whole worlds rose against Imperial rule, and communications with much of the Segmentum were lost.
Which famous worlds are in Segmentum Pacificus?
Colchis, Nova Terra, Tanith, Verghast, Sanctum and the forge world Xana are among the best known.