The Ultramarines are one of the most iconic and influential Space Marine Chapters in the universe of Warhammer 40,000. Known for their discipline, strategic brilliance, and unwavering loyalty to the Imperium of Man, they represent the ideal of what a Space Marine is meant to be: a superhuman warrior dedicated to protecting humanity against countless threats across the galaxy.
The Ultramarines trace their lineage to their Primarch, Roboute Guilliman. Guilliman was not only a legendary warrior but also a master administrator and tactician who authored the Codex Astartes the foundational text that defines the organization, strategy, and doctrine of most Space Marine Chapters.