Event · M31
Battle of Trisolian
The Battle of Trisolian was an Imperial engagement at the world of Trisolian in the thirty-first millennium, linked to the primarchs Leman Russ and Horus. It belongs to the closing phase of the Great Crusade, when the Emperor’s expeditionary fleets were still bringing scattered human and xenos-held worlds under Imperial rule. On Orrery it is anchored to Trisolian on the map and to the primarchs Leman Russ and Horus on the timeline. The record ties two of the Legiones Astartes’ foremost commanders to the engagement: Leman Russ of the Space Wolves and Horus of the Luna Wolves, later the Sons of Horus. Detailed accounts of its immediate cause, the strength of the forces engaged, and the sequence of its turning points are sparse, and accounts differ on how far each primarch was directly involved. This entry therefore describes the battle by its participants and setting and does not reconstruct an order of battle that the sources do not support. The battle is best read as a contemporary of the Great Crusade’s final campaigns, shortly before the Horus Heresy divided the Legions. Russ and Horus were later placed on opposing sides of that conflict, Russ carrying out the Emperor’s judgement against Prospero and Horus turning against the Throne, which gives any earlier cooperation between them particular weight in retrospect. Trisolian’s present condition and the lasting consequences of the fighting there are not firmly recorded, and readers should follow the links to the Space Wolves, the Sons of Horus and the Great Crusade for the surrounding chronology.
See where Battle of Trisolian occurred on the galactic map during the Horus Heresy.