u/Jazersances

Hi! I've heard in a lot of raven guard lore videos that Corax was taken and rised by slaves in Deliverance and that this shaped his "revolutionary" character of like fighting against leaders and so on ( i don't know if it is exactly like that). I would like to know in which books can I find this story and if these books, and generally all the books related to Corax from the Horus Heresy series, can be read by their own without reading all the other Horus Heresy books or if at least I should have a background of the first 5-7 books. Thank you!