A Britannian Forces officer working under Prince Clovis who was trying to solve the mystery behind C.C.'s immortality. After Prince Clovis' death he was sent to Britannia; but he returned under Prince Schneizel's orders to conduct experiments, such as altering Jeremiah's body. However, during the Black Rebellion, Jeremiah went haywire and escaped, thus resulting in another blunder for Bartley.
After that, he returned to Britannia and was forcibly summoned by the Geass Organization to make final adjustments on Jeremiah.
He became involved in Lelouch's Geass Organization Destroy Mission and perished. He led a checkered life from the time of his involvement with C.C., but he was loyal to the royal family until the end.