Space marine list

In the Warhammer 40k universe, there were originally 20 chapters of space marines. Two have been lost, leaving 18 today (meaning in the 41st millennium). There's a convenient even split within these 18 legions, with 9 being loyalist troops in service to the fascist Emperor and the other 9 being dedicated to the selfishness forces of chaos.

Because each chapter of space marine has factions within them, you do sometimes hear a lot of names being thrown around, and it can make it hard to remember what's at the top of the family tree.

This is a list of the 9 space marine loyalist chapters and the 9 traitor legions as they exist in the 41st millennium. They're listed by legion number, along with their primary colour scheme (using Contrast Paint name, when available from Citadel), a notable trait, and Primarch.

1. Dark Angels: Loyalist, Dark Angels Green, chivalry, Lion'el Jonson, combined arms
2. <Redacted>
3. Emperor's Children: Chaos, Syish Purple, Slaanesh, Fulgrim, combined arms
4. Iron Warriors: Chaos, Basilicanum Grey and Aggaros Dunes (silver and gold), Perturabo, siege, armoured assault, bombardment
5. White Scars: Loyalist, Apothecary White and Blood Angels Red, fast strike forces, Jaghatai Khan
6. Space Wolves: Loyalist, Space Wolves Grey (blue-grey), viking warriors, Leman Russ, close assault
7. Imperial Fists: Loyalist, Iyanden Yellow, defense, siege, Rogal Dorn
8. Night Lords: Chaos, Leviadon Blue and Aggaros Dunes (blue and brass), terror, counter-unsurgency, Konrad Curze
9. Blood Angels: Loyalist, Blood Angels Red, artistic blood lust, planetary assault, Sanguinius
10. Iron Hands: Loyalist, Black Templar (black and grey), augmetics, armoured assault, Ferrus Manus
11. <Redacted>
12. World Eaters: Chaos, Flesh Tearers Red and Aggaros Dunes (red and brass), close assault, Khorne, Angron
13. Ultramarines: Loyalist, Ultramarines Blue, space marines, combined arms, strategy, Roboute Guilliman
14. Death Guard: Chaos, Militarum Green, Nurgle, biological warfare, bombardment, heavy assault, Mortarian
15. Thousand Sons: Chaos, Akhelian Green and Iyanden Yellow (azure and yellow), Tzeentch and psykers, Magnus the Red
16. Black Legion: Chaos, Black Templar and Aggaros Dunes (black and gold), planetary assault, use but do not worship chaos, Horus
17. Word Bearers: Chaos, red and silver, first heretics and worships daemons, combined arms, garrison, Lorgar
18. Salamanders: Loyalist, Warp Lightning (Green), blacksmiths, anti-armour, incendiary, Vulkan
19. Raven Guard: Loyalist, Black Templar and Apothecary White, special ops and stealth, fast attacks, Corvus Corax
20. Alpha Legion: Chaos, blue, spy and subterfuge, special operations, counter-insurgency, Alpharius and Omegon

Lots of material to explore! You really get to know the Primarchs in the Horus Heresy books, and obviously the Black Library and Codexes have lots of material to read.