The great war of the Horus Heresy spanned the entire galaxy, and raged for an insane amount of time. Demi-gods and Gods clashed, while armies of super-soldiers waged war across an untold number of planets. The Horus Heresy was the darkest, and bloodiest war to ever engulf the galaxy. And you SHOULD be reading about it!
Why you should be reading Warhammer 40K The Horus Heresy Saga!
The Eternal Axiom 