In Eastern Orthodox iconography (and sometimes in the Western), Saint Christopher is sometimes represented with the head of a dog. The background to the dog-headed Christopher is laid in the reign of the Emperor Diocletian, when a man named Reprebus, Rebrebus or Reprobus was captured in combat against tribes dwelling to the west of Egypt in Cyrenaica. To the unit of soldiers, according to the hagiographic narrative, was assigned the name numerus Marmaritarum or "Unit of the Marmaritae", which suggests an otherwise-unidentified "Marmaritae" (perhaps the same as the Marmaricae Berber tribe of Cyrenaica).