Knights of the Cross
The Knights of the Cross, also known as the Knights of the Sword, are a group of people who wield one of three holy swords, each supposedly forged with one of the nails from the Crucifixion of Christ.
The exact prerequisite qualifications for being chosen are unknown. Harry Dresden’s working theory is that Knights are descendents of old royalty – which were the subjects of power in the old world. This would fit all the recent Knights known to him: Shiro is descended from the last king of Okinawa4, Sanya from Saladin4, Michael from Charlemagne5. So far, the swords have been temporarily used by at least two people of unknown descent, Karrin Murphy and Susan Rodriguez, which neither lends further proof nor unproof to Dresden’s theory.
Esperacchius was offered by Michael to the former Denarian Sanya, who accepted.
Shiro Yoshimo was killed in his last moments he gave the sword, Fidelacchius, to Harry Dresden for safekeeping, saying that he would know who to the next knight will be. Michael Carpenter was gravely injured on Demonreach. Afterwards he chose to retire from active Knight duty, also giving his sword to Dresden. Sanya is the only active Knight left.
The two swords in Dresden’s care were temporarily used, Fidelacchius by Karrin Murphy and Amoracchius by Susan Rodriguez.