[The power of the four Prætorian Præfects in the time of Constantine is thus described by Gibbon: “1. The Præfect of the East stretched his ample jurisdiction into the three parts of the globe which were subject to the Romans, from the cataracts of the Nile to the banks of the Phasis, and from the mountains of Thrace to the frontiers of Persia. 2. The important provinces of Pannonia, Dacia, Macedonia, and Greece once acknowledged the authority of the Præfect of Illyricum. 3. The power of the Præfect of Italy was not confined to the country from whence he derived his title; it extended over the additional territory of Rhætia as far as the banks of the Danube, over the dependent islands of the Mediterranean, and over that part of the continent of Africa which lies between the confines of Cyrene and those of Tingitania. 4. The Præfect of the Gauls comprehended under that plural denomination the kindred provinces of Britain and Spain, and his authority was obeyed from the wall of Antoninus to the fort of Mount Atlas.”—Decline and Fall, chap. 17.— Bag.]