The Horus Heresy is the bloodiest conflict humanity has ever known, a galactic civil war in which Space Marines of the Legiones Astartes turn devastating weapons upon those they once called brothers.
Always in the thickest of the fighting, Legion Tactical squads are highly flexible infantry units, able to attack or defend at will, assault heavily fortified positions, and take and hold strategic objectives. A wide array of war machines, such as the Deredeo pattern Dreadnought and the Land Raider Proteus, would often support these ranks.
