Legiones Astartes Dusk Raiders – Furibundus-class Dreadnought Ancient Adrætan.

As the Great Crusade ground on the earlier classes of dreadnoughts and proto-dreadnoughts began to be replaced by the more sophisticated Contemptor and Deredeo patterns, and the easier to manufacture Castraferrum. At the time there were fears, chiefly amongst the Mechanicum, that the knowledge required to manufacture these earlier models, many of which could be piloted by non-Astartes, would be lost. Consequently, many were recalled to Mars to aid the Mechanicum in cataloguing and recording their systems for posterity. However, later research shows that this recall was almost entirely amongst those legions who would later side with Horus during the heresy and handled exclusively by the tech-covens who would go on to form the core of the Dark Mechanicum – Given that the majority of the older classes were piloted by the original Terran inductees of the Legions, it seems likely that this in fact represents the first, quiet effort to purge the Legions of Terran loyalists. In light of this, it may well be that Ancient Adrætan was among one of the first victims of the Heresy.