Spiked armour, daemonic weapons and ten thousand years of hatred: Chaos Space Marines are the dark mirror of the Imperium's heroes. This guide answers one question: who are the Chaos Space Marines, and what are the Traitor Legions?
The short answer
Chaos Space Marines are Space Marines who turned against the Emperor. Most descend from the nine Legions that sided with the Warmaster Horus during the civil war known as the Horus Heresy. Defeated, they fled into the Eye of Terror, a vast warp rift where time flows strangely, and many of them are still alive and fighting today.
How the Legions fell
Space Marines were first organised into twenty Legions, each created from the gene-seed of one of the Emperor's sons, the Primarchs. During the Great Crusade, Horus, the most favoured Primarch, was corrupted by the Chaos Gods and turned on his father. Eight other Primarchs and their Legions followed him. The rebellion ended with the Siege of Terra, where Horus was slain, and the traitors retreated.
The loyal Legions were then broken into smaller Chapters. The traitors were not, which means the Traitor Legions are, strictly speaking, the only Space Marine Legions still in existence. Over the millennia, though, most have splintered into rival warbands following individual Chaos champions.
The nine Traitor Legions at a glance
The colour column is our own generic painting guide to each Legion's classic look (base / shade / highlight). Colour schemes have changed over the Legions' long history, so treat these as starting points.
| Legion | No. | Primarch | Allegiance | Classic colours (base / shade / highlight) |
|---|---|---|---|---|
| Emperor's Children | III | Fulgrim | Slaanesh | Purple or pink armour / dark purple wash / lilac edges, with lots of gold |
| Iron Warriors | IV | Perturabo | Chaos Undivided | Gunmetal / black wash / bright silver edges, with yellow-and-black hazard stripes |
| Night Lords | VIII | Konrad Curze | Chaos Undivided | Midnight blue / black wash / blue-grey edges, with red lightning bolts |
| World Eaters | XII | Angron | Khorne | Blood red / dark red-brown wash / orange-red edges, with brass |
| Death Guard | XIV | Mortarion | Nurgle | Off-white or pale green / brown-green wash / pale highlights, with rust and corrosion |
| Thousand Sons | XV | Magnus the Red | Tzeentch | Rich blue / dark blue wash / light blue edges, with gold |
| Black Legion (formerly Sons of Horus) | XVI | Horus | Chaos Undivided | Black / black wash for depth / grey edges, with gold trim |
| Word Bearers | XVII | Lorgar | Chaos Undivided | Deep crimson / dark red-brown wash / red edges, with black and gold |
| Alpha Legion | XX | Alpharius | Chaos Undivided | Blue-green / dark green-blue wash / turquoise edges, with silver |
Wait, isn't the Black Legion a tenth Legion?
No, and this trips up a lot of newcomers. The Black Legion is the old Sons of Horus Legion (originally called the Luna Wolves). After Horus died, his former First Captain, Abaddon, eventually renamed the Legion, painted its armour black and rejected the name of their fallen Primarch. It is the only Traitor Legion to have changed its name. Abaddon, now called the Despoiler, has since led a series of Black Crusades against the Imperium.
Undivided and god-aligned Legions
Four Legions are devoted to a single Chaos God: the World Eaters to Khorne, the Death Guard to Nurgle, the Thousand Sons to Tzeentch and the Emperor's Children to Slaanesh. These four now have their own army rules. The other five are usually described as "Chaos Undivided", meaning they worship the Chaos pantheon as a whole or use it for their own ends.
What do Chaos Space Marines want?
- Revenge: many still blame the Emperor and the Imperium for their exile.
- Power: Chaos rewards ambition, and champions dream of becoming immortal daemon princes.
- Survival: some warbands are little more than raiders and pirates, fighting for weapons, slaves and supplies.
Painting tips for traitors
- Start from a Legion scheme, then corrupt it. Clean Legion colours plus a little rust, grime and battle damage instantly read as "ten thousand years of war".
- Use washes for age. Oil washes are excellent for pooling grime into armour recesses.
- Pick a spot colour for Chaos icons. Glowing eyes, warp flames or a single bright trim colour helps a dark army pop on the table.
Comparing them with their loyal brothers is half the fun: see our guide to Space Marine Chapters for the loyalist side.
Common beginner questions
Are Chaos Space Marines all from the original nine Legions?
No. Over ten thousand years, whole Chapters and individual Space Marines have also turned traitor. Many warbands mix renegades with Legion veterans.
Are the original traitors really still alive?
Some are. Time flows unpredictably in the Eye of Terror, so warriors who fought in the Heresy can still be fighting in the 41st and 42nd millennia.
Can I invent my own warband?
Yes. Renegade warbands are everywhere in the setting, so a homemade warband with its own colours fits perfectly.
Quick summary
- Nine Space Marine Legions sided with Horus during the Heresy and became the Traitor Legions.
- The Black Legion is the renamed Sons of Horus, not a tenth Legion.
- Four Legions serve a single Chaos God; the rest are usually called Chaos Undivided.
Independent resource published by Blubbercove Ltd. This page is not affiliated with, sponsored by, endorsed by, authorised by or licensed by Games Workshop Limited.
Warhammer 40,000 and the names of all associated armies, characters, races, vehicles, units and places are trademarks of Games Workshop Limited, used here without permission and solely to identify the subject. This is an unofficial fan guide.