Santor hailed from the Avernii Clan on the X Legion's homeworld of Medusa. He served as the First Captain of the elite 1st Company of the Iron Hands Legion during the majority of the Great Crusade in the late 30th and early 31st Millennia. A stoic and devout warrior, Ferrus Manus valued the sage wisdom and advice of his favoured son Gabriel, who helped rein in his Primarch's fiery temper. In this capacity, Santor had also been appointed to serve as Equerry to the Primarch. First Captain Santor did not possess the phenomenal temper of his Primarch but he was as harsh and unyielding as the bionics in his limbs. He also had the honour of leading Manus' personal bodyguard of staunch praetorians, the Morlocks. As with most things, Ferrus Manus did not have the time or inclination for patience.