Arceas Odinathus had become Chapter Master of the 10th Chapter at the time of the Horus Heresy and was personaly dispatched by Roboute Guilliman to the northern regions of Ultima Segmentum to purge garrison forces left by the World Eaters and Word Bearers in the wake of the Shadow Crusade. In addition to the 10th Chapter, his command included Seekers from the 88th Company. Establishing a command post on the forge world Gulgorahd, he eliminated the World Eaters on Taur in an ambush and annihilated the Word Bearers on Caith Laes before suffering a defeat at the hands of the Night Lords in 011.M31 that claimed much of the 104th and 108th Companies.
Based on intelligence gathered from stragglers of the Dark Angels fleet, Odinathus gathered the 10th Chapter along with Destroyers from the 22nd "Nemesis" Chapter, seven taghma of the Taghmata Gulgorahd and a mixed company of Blood Angels and Iron Hands for a strike against an expected twelve companies of Night Lords at Desperation. Finding more resistance than expected, Odinathus' force quickly lost the initiative both in orbit and on the surface in the Battle of Desperation. The sudden arrival of an unmarked Space Marine fleet that all but destroyed the Night Lords in orbit, but their Praetor Kirine disavowed loyalty to either the Warmaster or the Imperium. Odinathus attempted to avoid a three-way conflict until the Ashen Claws attacked the principal armourium held by the Ultramarines, forcing their retreat in a counter-attack. To prevent further losses, the Ashen Claws and Ultramarines retreated, with the Ultramarines launching an orbital bombardment on the surface.