

The Codex Astartes details the proper organisational structure and mobilisation methods for a Space Marine Chapter. The majority of Space Marine Chapters follow the dictates of the Codex Astartes, a sacred tome written by the Ultramarines Primarch Roboute Guilliman. Most Chapters have feudal title to an entire planet of the Imperium which serves as its Chapter homeworld or to a large fleet of powerful and massive starships that serves as a mobile headquarters if the Chapter is fleet-based.

Every Chapter is entirely autonomous from every other adepta of the Imperium, including the Inquisition, and takes its orders only from the High Lords of Terra themselves. Each Chapter serves collectively with the others of its kind as part of the Imperium of Man's Adeptus Astartes. The Ultramarines, the archetypal Codex Astartes-compliant Space Marine Chapter, gathered for war.Ī Chapter is a completely autonomous military unit made up of one thousand transhuman warriors known as Space Marines and their related vehicles, starships and support personnel. High Lord Tagus, Convenor of the 349th Congress of the Imperium

" Such is the woe cast upon the Domains of the God-Emperor of Mankind in these times that in their wisdom and beneficience, the High Lords of Terra have this day issued this decree: Let there be a Founding of the Adeptus Astartes, and let the foes of the Emperor know that this galaxy belongs to Him, now and forever."
