Founding of the Grey Knights

In the last days of the Heresy Malcador found twelve worthy — four lords and eight Astartes psykers from the loyalist and traitor Legions, who had renounced their former oaths. The four lords laid the foundation of the Inquisition, and the eight warriors went with Malcador to Saturn’s moon Titan, where they became the first Grand Masters of the Grey Knights; Janus was named the first Supreme Grand Master. Malcador concealed Titan itself in the warp behind Geller macro-fields.