I'm sure there are more essential books after but I don't want to comment on books I've not completed.Įach book functions as a standalone story, you'll get more out of them with the extra context from other books but it isn't necessary to enjoy them.

Not everyone likes the Ultramar side story but I think it does a good job of explaining why Guilliman isn't more involved in the Heresy.īook 23: Angel Exterminatus covers Fulgrim becoming a Daemon Prince and it's a good read for Perturabo fans.īook 41: Master of Mankind gives us more Emperor content than every book that comes before combined.īook 42: Garro sets up the Grey Knights and is generally a great read. I genuinely feel that every book adds something unique to the tapestry of the Horus Heresy but I'll do my best to answer your question.īooks 1-5 are quite important for setting up the Heresy.īook 9: Mechanicum covers the initial fall of Mars.īook 12: A Thousand Sons is very important because it explains why the Emperor is kept out of a lot of the Heresy.īook 14: The First Heretic covers how Lorgar fell to Chaos.īook 19: Know no Fear is a little controversial. I've listened to every novel from book 1 to 44 and I plan on going through every book in the series.

Horus heresy novels