The Horus Heresy, a war between Gods and Daemons, Immortals and men. The Heresy is the single most important event in the Warhammer 40k universe. From its ashes rises the Imperium of Man and it's eternal war against those it once called it's favored sons.
Prior to the Heresy however, was The Great Crusade. After unifying Terra with the use of his Thunder Warriors, the Emperor set out from to reunite humanity, and reclaim the darkness in the name of science. Alongside the Emperor walked his truest sons, the Primarchs. The Primarchs, and their roles, will be the subject that I discuss today.
For anyone that has read Prospero Burns by Dan Abnett, the “role” of the Space Wolves is made very clear. They are the Emperor's Executioners. They are the ones he sends to sanction any other Astartes Legion that fails to heed his word. This revelation really got me to think about some of the other roles the Emperor may have had in mind for the remaining Legions at their inception. Please note that while I base my thoughts off of reading the Horus Heresy series and various other tomes of knowledge, much of this is pure speculation, either their roles during the Crusade or after.
The Warmaster, the charismatic leader that could hold the Crusade together while the Emperor completed his work.
Fulgrim /Emperor's Children – The Artisan.
Portubo / Iron Warriors – The Empires garrison, the ones that would build the defenses.
Mortarion / Death Guard – Hostile environment warriors, but also warriors that would be implacable in their war making.
Night Haunter / Night Lords – The ones sent to deal the terrible justice that no one else could, the ones that would be the terror weapons.
Magnus / The Thousand Sons – The scholars and the mages.
Alpherus / Alpha Legion – Covert Ops, those that would work in the shadows.
Angron / World Eaters – The Berserkers, the world killers. Imperial Armor even mentions how before they became the World Eaters the War Dogs were kept in reserve unless something needed to be destroyed totally and completely.
Logar / Word Bearers – The Scribes, but also a battle force. With secularism the new black in the world of 30k there couldn’t really have been much more to say about them.
Guilliman / Ultramarines – The bureaucrats, the warriors that could/would become planetary lords.
Sanguinius / Blood Angels – The spiritual inheritor of the Emperors wil.
Khan / White Scares – The huntsman, those that would bring any to justice no matter where they went.
Dorn / Imperial Fists – The Praetorians. The ones that would guard ancient terra and the Emperor alongside the Custodus
Ferrus Manus / Iron Hands – The forgesmiths, the ones that would continue to work alongside the Mechanicum to produce the Empires arsenal.
Vulkan / Salamanders – The Protectors, the ones that truly cared about the average citizenry.
Corax / Raven Guard – The gorilla warriors, often working alongside the Alpha Legion
Russ / Space Wolves – The Executioners.
The Lion / Dark Angels - Battle Line legion.
As I have said this is all my own thoughts on each Legion. Some of my thoughts are centered on the Primarch, some on the legion as a whole. But perhaps when the Emperor created the Legions he had specific ideas for each one. What would you say?