Alpharius

Alpharius was a primarch of the Imperium of Man and, with his twin Omegon, commander of the Alpha Legion, the XX Legion of Space Marines. Accounts of his rediscovery disagree sharply, and no homeworld for either twin has been established with confidence. The conventional Imperial narrative holds that Alpharius was the last of the primarchs found, encountered by Horus Lupercal during the Great Crusade and only afterwards brought before the Emperor on Terra; Horus is said to have kept him for some months before that meeting. A separate tradition, set out in the account known as Head of the Hydra — which Alpharius himself is recorded as calling a lie even while telling it — places Alpharius’s early years on Terra, found by the Emperor on the Zhari Namco Plateau and raised in secrecy with Malcador the Sigillite, while Omegon grew up alone on an empty world far from Imperial space. Legends that place his youth with the Emperor on Terra therefore exist beside the last-found tradition; neither is settled by a single authoritative record.

The circumstances of his presentation to Horus are likewise disputed. Warmaster-era accounts describe a primarch boarding the Vengeful Spirit, forcing Horus’s intervention, and declaring himself Alpharius. Head of the Hydra instead holds that the figure who took that name before Horus was Omegon, while Alpharius remained unseen. Both versions agree that whichever twin appeared did so without openly revealing the dual nature of the Legion’s command.

In the Great Crusade the Alpha Legion developed a doctrine of infiltration, misdirection and non-Astartes operatives that other primarchs often found difficult to accept. Alpharius personally commanded the Tesstra Compliance against the Tesstra Conservation, delaying a full assault until a single devastating strike shattered the capital at Prime. He fought with the 670th Expedition on Nurth, where the Nurthene activation of a Black Cube ruined the world and where, in related accounts, the xenos Cabal first approached Alpharius Omegon with visions of the coming civil war, roughly two years before the Horus Heresy. In 999.M30, during the World Prince Campaign, Alpha Legion methods of destabilisation and assassination brought Alpharius into open disagreement with Rogal Dorn over the conduct of compliance warfare. After the Heresy opened he is recorded as commanding Alpha Legion forces that trapped Leman Russ’s Space Wolves in the Alaxxes Nebula, and as fighting Russ while disguised as one of his own Lernaean Terminators before Dark Angels intervention forced a withdrawal.

During the early Solar War Alpharius led the Alpha Legion strike on Pluto and its moons. On the moon Hydra he fought Rogal Dorn in personal combat and, in the account given by Praetorian of Dorn, was killed there in 010.M31. Far away, Omegon is held to have sensed that death and thereafter assumed the name Alpharius within the Legion. A later Imperial tradition places the death of a primarch wearing the Alpharius name on Eskrador at the hands of Roboute Guilliman during the Scouring; which twin died there, if either did, and how that account sits beside the Pluto duel, remains contested even among the Ultramarines and within the Alpha Legion. Alpharius’s status after these reported deaths is unknown.