Galadin was a Company Master in the Dark Angels Chapter. Before he attained his current rank, Galadin was a Sergeant who was part of the strike force his Chapter sent to take part in the Pyrus Reach Conflict. As the Dark Angels joined the battle, Galadin was dispatched to the Imperium Colony World Vilhan III, with a detachment of the Cadian Imperial Guard led by Captain Lucien, to determine the measure of the Chaos incursion into the region. That and to secretly search for the Fallen Cypher, whose sighting in the beleaguered Sector led to the Dark Angels' involvement in the first place. When Galadin finally reached Vilhan III however, he received an unwanted surprise, as the world was being raided by Orks.
Galadin knew well of the savagery the Orks were capable of, having fought them before on Haladrom Prime, a battle that left him the only survivor of his squad, and did not hesitate to deploy his heavily outnumbered forces; in order to save Vilhan III's remaining colonists. Galadin and the Dark Angels quickly set up a defensive perimeter, near Vilhan III's remaining colony and had Captain Lucien and his Cadian troops hide nearby. As the Orks attacked the Dark Angels drew them in close to them, before Galadin gave the order for Lucien and his troops to emerge from hiding and attack the Orks from behind. Suddenly finding themselves caught between the Dark Angels and Cadians, the Orks were caught off guard and were completely destroyed; leaving Vilhan III safe for the time being. After the successful defense of Vilhan III, Galadin continued fighting in the Pyrus Reach Sector and later attained the rank of Company Master. He was then charged with killing the Dark Apostle Valerius, who was leading an overwhelming attack on the Imperium World Hyrus Prime. Though Galadin successfully led a Dark Angels' strike force in boarding Valerius' vessel, the Eternal Pain, as it was in Hyrus Prime's orbit; he failed in his attack and the world fell to the Dark Apostle's forces. Whether Galadin died aboard the Eternal Pain, or was able to escape, is not known.