Khalid is the only military leader who fought more than 200 undefeated battles and is considered to be one of the finest military leaders in history.[3] Narses (478–573) - ethnic Armenian, he was, with Belisarius, one of the great generals in the service of the Byzantine Emperor Justinian I during the Roman reconquest that took place during Justinian's reign, where he succeeded in recapturing Rome from the Ostrogoths. The last general to receive a Roman triumph in Rome.