Eras
The great epochs that carve up the history of Warhammer 40,000: the ages, crusades, and cataclysms that shaped the setting.
- ~60 Million Years Ago
The War in Heaven
A primordial galactic war between the deathless Necrons and their C'tan star-gods and the ancient Old Ones and their servants, which scarred the galaxy forever.
- M15–M25
The Dark Age of Technology
Humanity's golden age of interstellar expansion and boundless science, when mankind mastered the stars before hubris and rebellion brought it crashing down.
- M25–M30
The Age of Strife
Five thousand years of isolation, warp storms, and horror when the tides of Chaos cut Terra off from the stars and humanity nearly perished.
- M30–M31
The Great Crusade
The Emperor's grand campaign to reunite the scattered worlds of humanity beneath a single enlightened rule and cast down the darkness of superstition.
- M31
The Horus Heresy
The galaxy-spanning civil war in which the Warmaster Horus turned half the Emperor's Legions to Chaos and brought the Imperium to the brink of ruin.
- M31–M32
The Scouring
The bitter aftermath of the Heresy, when the victorious loyalists hunted the broken traitor Legions into the Eye of Terror and beyond.
- M32–M41
The Age of the Imperium
Ten thousand years of grinding war, dogma, and slow decline as the Imperium hardened into a xenophobic theocracy ruling a million worlds by faith and fear.
- Late M41
The Time of Ending
The apocalyptic close of the forty-first millennium, when every ancient enemy stirred at once and the galaxy seemed poised to fall into final darkness.
- M42
The Era Indomitus
The present age of the sundered galaxy, split by the Great Rift, defended by the reborn Primaris legions and the returned primarch Roboute Guilliman.