Timeline of the Milky Way galaxy:
- Ancient history
- M1 - Age of Terra begins
- M2
- M3
- M4
- M5
- M6
- M7
- M8
- M9
- M10
- M11
- M12
- M13
- M14
- M15 - End of the Age of Terra and beginning of the Dark Age of Technology
- M16
- M17
- M18 - Second Dark Age of Technology
- M19
- M20
- M21
- M22 - Third Dark Age of Technology
- M23
- M24
- M25 - End of the Dark Ages of Technology and beginning of the Age of Strife.
- M26 - Second Age of Strife
- M27
- M28
- M29
- M30 - Fall of the Eldar, and birth of Slaanesh. The Ages of Strife ends and Age of the Imperium begins. Creation of the Space Marine Legions.
- M31 - Great Crusade begins, and ends after 200 years of conquest because of the Horus Heresy. Also includes the Great Scouring and the Age of Imperium begins.
- M32
- M33
- M34
- M35
- M36 - Age of Apostasy
- M37
- M38
- M39
- M40
- M41 - Time of Ending begins.
- M42