The Astra Militarum regiments are the countless fighting units raised by the Imperium’s worlds, each shaped by its homeworld’s culture and warfare. They’re the backbone of the Imperial Guard and the reason no two Guard armies look or fight the same.
What the astra militarum regiments actually are
A regiment is a raised formation of soldiers, usually tied to a single world or system. The Imperium calls them Astra Militarum; most fans still say Imperial Guard.
Every regiment gets its character from where it’s from. Ice worlds produce hardened infantry, hive worlds produce urban fighters, and forge worlds turn out armoured units. That’s why the lore lists them by homeworld: the planet tells you how they fight.
Why they matter
The regiments are the Imperium’s mass army. Space Marines get the glory, but Guard regiments hold the line, soak up casualties, and win wars through numbers and grit.
They’re also the most human part of 40k. A regiment’s name, nickname, and battle history say more about the setting’s scale than any primarch ever could.
How regiments are organised
Most regiments carry a number and a homeworld name, like the 8th Amartine Scout Cavalry or the 98th Athonian Tunnel Rats. Some earn nicknames, and some are penal legions made of convicts.
Specialisations vary just as widely. You’ll find infantry, armour, artillery, siege, cavalry, and abhuman units, each with its own traditions and reputation.
- Infantry: the standard line regiments, raised in huge numbers.
- Armoured: tank-heavy formations, often from industrial worlds.
- Siege: specialists in breaking fortified positions.
- Penal legions: convicts given a chance to die for the Emperor.
- Abhuman: Ogryn, Ratling, and other non-standard troops.
Notable examples from the lore
Some regiments are famous enough to have their own stories. The Armageddon Steel Legion are mechanised infantry from a war-torn hive world, while the Athonian Tunnel Rats fight in the darkness beneath the streets.
Others, like the 13th Penal Legion, the Last Chancers, are defined by their criminal pasts. The list goes on for pages, and that’s the point: the Imperium has more regiments than anyone can count.
| Regiment | Homeworld | Specialty |
|---|---|---|
| Armageddon Steel Legion | Armageddon | Mechanised infantry |
| Athonian Tunnel Rats | Athonos | Underground warfare |
| 13th Penal Legion | Various | Penal conscripts |
| 8th Amartine Scout Cavalry | Amartine | Reconnaissance |
Key facts
- Regiments are raised by individual worlds, so their homeworld shapes their tactics and culture.
- The Astra Militarum is the Imperium’s main mass army, and the Imperial Guard is the same organisation under an older name.
- Regiments cover infantry, armour, artillery, siege, cavalry, penal, and abhuman roles.
- Famous examples include the Armageddon Steel Legion and the Athonian Tunnel Rats.
- The full list of named regiments runs to hundreds, and it’s still growing.
FAQ
What’s the difference between the Astra Militarum and the Imperial Guard?
They’re the same thing. Astra Militarum is the official High Gothic name, and Imperial Guard is the older, more common term fans still use.
How many Astra Militarum regiments are there?
Nobody knows. The lore lists hundreds by name, but the Imperium raises countless more across its worlds, and most never get recorded.
Can I make my own regiment?
Yes. Homebrew regiments are a huge part of the hobby, and the lore actively encourages you to invent a homeworld, a name, and a fighting style.