Lochos

Lochos is a world of Ultramar, the star-dominion built by the Ultramarines Legion in the Ultima Segmentum during the Great Crusade. It is counted among the Five Hundred Worlds brought under Roboute Guilliman’s administration, the network of compliant and reclaimed systems bound together by Ultramarines garrisons, fleets, and the codified governance that distinguished Ultramar from the wider Imperium. As with many of these worlds, Lochos’s population and institutions were shaped by the Legion’s practice of direct oversight, with local defence and civil order woven into the broader Ultramar military structure rather than left to a single planetary authority.

Lochos’s significance lies chiefly in its place within this Ultramarines theatre during the era spanning the Great Crusade and the Horus Heresy, when Ultramar’s internal cohesion and defensive depth were tested by the wider galactic crisis following Horus Lupercal’s rebellion. Worlds of this kind served as mustering points, supply nodes, and lines of defence as Roboute Guilliman withdrew forces inward to consolidate the dominion against the possibility of Traitor incursion, a process that reshaped the strategic map of Ultramar in the years after the Isstvan atrocities and the assault on Calth. Specific campaigns fought at Lochos itself are not widely attested, and later accounts of the period should be treated with appropriate caution where detail is sparse.

As a constituent world of Ultramar, Lochos sits within the same web of contemporaries as Calth, Macragge, and the other Five Hundred Worlds, all bound to the authority of Roboute Guilliman and the Ultramarines Legion. Its recorded status is that of an Ultramar system administered under Legion oversight through the Great Crusade and Horus Heresy period; later developments affecting the world are not established in the material currently available.