The Cadian Gate is the stretch of space that once served as the only reliable doorway between the Eye of Terror and the rest of the galaxy. For ten thousand years it was the Imperium’s most important chokepoint, and when it broke, it tore the galaxy in half.
What the cadian gate actually was
Think of the Eye of Terror as a permanent wound in reality. Warp storms rage inside it, but here and there the edge calms down enough for ships to slip through. The Cadian Gate was the calmest, most predictable of those gaps, sitting to the galactic south-east of the Eye.
It wasn’t the only way out. The Arx Gap offered another route, just a less stable one. But for Chaos fleets wanting a reliable path into realspace, the Cadian Gate was the one that mattered.
- Located south-east of the Eye of Terror
- Only predictably stable exit from the Warp rift
- Made possible by the blackstone pylons buried beneath Cadia’s surface
- Constant target of Chaos raids for ten millennia
Why Cadia’s pylons held the door shut
The Gate existed because of the blackstone pylons on Cadia itself. These ancient structures reinforced the barrier between realspace and the Warp, keeping the corridor narrow and navigable rather than letting it bleed open into a full rift.
That’s why Cadia was fortified so heavily. The planet wasn’t just a fortress world by choice, it was the plug in the drain.
The fall and the Cicatrix Maledictum
During the 13th Black Crusade, Abaddon the Despoiler crashed a Blackstone Fortress into Cadia and destroyed it. With the planet gone, the pylons went with it, and the Cadian Gate collapsed.
The result was the Cicatrix Maledictum, the Great Rift that split the Imperium in two. The Gate didn’t just close, it failed catastrophically.
Even so, the region is still an active warzone. Chaos keeps expanding its holdings there, and the surviving Imperial worlds keep resisting. Major flashpoints since Cadia’s destruction include the War of the Spider, further attacks on Agripinaa, the Siege of Belis Corona, and pushes by Indomitus Crusade Fleet Secundus and the Heimdel Crusade.
Major systems of the cadian gate
The Gate wasn’t a single place. It was a region containing several key systems, each with its own role in the defence.
| System |
|---|
| Cadia |
| Agripinaa |
| Belis Corona |
| Gudrun |
| Thracian Primaris |
| Chinchare |
| Toros |
| Trove |
| Olaedros |
| Vendara |
Related lore
The Cadian Gate sits alongside a few other named passages and organisations in Imperial history. The Boros Gate, Attilan Gate, and Nachmund Gauntlet are other corridors or chokepoints with their own stories. The Ordo Aegis, a Chaos-hunting branch of the Inquisition, was closely tied to watching over the Gate.
Key facts
- The Cadian Gate was the only stable passage out of the Eye of Terror
- Its stability came from blackstone pylons buried on Cadia
- Abaddon destroyed Cadia in the 13th Black Crusade by crashing a Blackstone Fortress into it
- The Gate’s collapse triggered the formation of the Cicatrix Maledictum
- The region remains an active warzone after Cadia’s fall
- Key systems included Cadia, Agripinaa, Belis Corona, and Gudrun
FAQ
What was the Cadian Gate?
It was the only predictably stable route between the Eye of Terror and realspace, kept open by blackstone pylons on Cadia. For ten thousand years it was the Imperium’s most critical defensive chokepoint.
Why did the Cadian Gate collapse?
Abaddon destroyed Cadia during the 13th Black Crusade by ramming a Blackstone Fortress into it. Without the planet’s pylons, the barrier between realspace and the Warp failed, creating the Cicatrix Maledictum.
Is the Cadian Gate still important after Cadia’s destruction?
Yes. The region remains a major warzone, with Chaos expanding its territory and Imperial forces fighting back through campaigns like the War of the Spider and the Indomitus Crusade.