Her Senate had lost the last remnant of its respectability.

Seeing the necessity of a more united country and a firmer rule, DIOCLETIAN associated with himself MAXIMIAN, a gigantic soldier, who signalized his accession by subduing a dangerous revolt in Gaul.

He also appointed two officers, GALERIUS and CONSTANTIUS, whom he called CAESARS,--one to have charge of the East, and the other of the West.

By means of these assistants he crushed all revolts, strengthened the waning power of the Empire, and imposed peace and good order upon the world.
Diocletian and Maximian afterwards resigned, and allowed their two Caesars to assume the rank of AUGUSTI, and they in their turn appointed Caesars as assistants.
Soon after his accession Constantius died, and his son CONSTANTINE was proclaimed Caesar, against the wishes of Galerius.

A bitter struggle followed, in which Constantine finally overcame all his opponents, and was declared sole Emperor.