The new codex features the most exhaustive background and bestiary for the Space Marines ever compiled into a single book. The origins and purpose of the Primaris Marines have also been covered in intimate detail, including their creation by the genius of Belisarius Cawl and their role within the Indomitus Crusade, as well as their integration within the existing Chapters and creation of new Chapters through the Ultima Founding.

A 192 page hardback rulebook that contains background, rules and datasheets for units that are common to all Codex Space Marine Chapters.