The Era Indomitus is the current period of Imperial history in Warhammer 40k, also called the Age of the Dark Imperium. It began with the destruction of Cadia in the Thirteenth Black Crusade and the birth of the Great Rift, splitting the Imperium in two.
Overview
The Era Indomitus is the latest chapter in the Imperium’s long story, following the Time of Ending. It kicked off when Cadia fell during Abaddon’s Thirteenth Black Crusade, tearing a warp rift across the galaxy that’s known as the Great Rift.
That rift cut the Imperium in half. One side, Imperium Nihilus, is stranded and desperate. The other side holds on thanks to Roboute Guilliman, the revived Primarch who’s been running the show since he woke up.
How it started and why it matters
Before this era, the Imperium was already crumbling. The 13th Black Crusade broke Cadia, and the Great Rift followed, creating the Noctis Aeterna (a period of total warp darkness) and splitting the galaxy. Guilliman’s return was the turning point. He launched the Indomitus Crusade to reclaim lost worlds and push back the chaos.
This era matters because it’s the first time in ten thousand years that the Imperium has a primarch leading it again, and it’s the setting for most modern 40k stories, from the Plague Wars to the Arks of Omen.
Key events of the Era Indomitus
The era is packed with galaxy-shaking conflicts. Here are the big ones:
- The Noctis Aeterna and the formation of Imperium Nihilus
- Roboute Guilliman’s Indomitus Crusade
- The Third War of Armageddon, where Orks and Imperials united against daemons
- The Invasion of the Stygius Sector
- The War of Beasts on Vigilus
- The Psychic Awakening
- The Charadon Campaign
- The Nachmund Rift War
- The Octarius War
- The Plague Wars
- The Devastation of Baal
- The Arks of Omen Campaign
- The Fourth Tyrannic War
When exactly is it?
The exact millennium is a bit fuzzy. The 13th Black Crusade is dated 999.M41, so you’d think the Era Indomitus is M42. Some in-universe historians even call it that.
But Games Workshop has deliberately left it uncertain. They’ve said the exact millennium can’t be pinned down, so you’ll see M42 used as a placeholder, but it’s not officially confirmed. That ambiguity is part of the setting’s charm.
Key facts
- The Era Indomitus is also known as the Age of the Dark Imperium.
- It began with the destruction of Cadia in the Thirteenth Black Crusade and the formation of the Great Rift.
- The Imperium is split in two by the Great Rift, with one half becoming Imperium Nihilus.
- Roboute Guilliman returned and launched the Indomitus Crusade to reclaim lost worlds.
- The exact millennium (M41 or M42) is intentionally left uncertain by Games Workshop.
FAQ
What is the Era Indomitus?
It’s the current period in Warhammer 40k, also called the Age of the Dark Imperium. It started after Cadia fell and the Great Rift formed, and it’s defined by Roboute Guilliman’s return and the Indomitus Crusade.
When does the Era Indomitus take place?
It begins right after the 13th Black Crusade in 999.M41. Most sources treat it as M42, but Games Workshop has left the exact millennium deliberately vague.
What is Imperium Nihilus?
It’s the half of the Imperium cut off by the Great Rift. It’s isolated, dangerous, and basically on its own, while Guilliman focuses on the other side.