From the blog "Bouargh´s miniatures´ closet clean-up"
Alongside the elite Skitarii regiments, whose allegiance and command was owed ultimately to Mars, and the Collegia Titanica, which comprised the planet-shattering
Titan Legions, both of which organisations operated separate military traditions of their own, the Taghmata formed the great trinity, the ‘Triad-Magna’, of the Mechanicum’s power during the Great Crusade. Besides these three there stood the ‘lesser’ independent and allied divisions of the Mechanicum such as the Knight Houses, the Ord