surpers, as well as to relieve
the Augusti of a part of their military and administrative burdens, he
determined to appoint two Caesars as the assistants and destined
successors of Maximian and himself. His choice fell upon Gaius Galerius
and Flavius Valerius Constantius, both Illyrian officers of tried military
capacity. They received the title of Caesar on 1 March, 293 A. D. To
cement the tie between the Caesars and the Augusti, Diocletian adopted
Galerius and gave him his daughter in marriage, while Maximian bound
Constantius to himself in the same way. It was the plan of Diocletian that
the Augusti should voluntarily abdicate after a definite period, and be
succeeded by the Caesars, who in turn should then nominate and adopt their
successors.

*The division of the empire.* To each of the four rulers there was
assigned a part of the empire as his particular administrative sphere.
Diocletian took Thrace, Egypt and the Asiatic provinces, fixing his
headquarters at Nicomedia. Maximian received Italy, Raetia, Spain and
Africa, and took up his residence at Milan. To Galerius were allotted the
Danubian provinces and the remainder of the Balkan peninsula, with Sirmium
as his residence; while Constantius, to whose lot fell the provinces of
Gaul, established himself at Treves. However, this arrangement was not a
fourfold division of the empire, for the Caesars were subject to the
authority of the Augusti, and imperial edicts were issued in the name of
all four rulers. Additional unity was given to the government by the
personal ascendancy which Diocletian continued to maintain over his
associates. One result of this arrangement was that Rome ceased to be the
permanent imperial residence and capital of the empire, Milan and later
Ravenna being preferred as the seat of government for the West. This
change was largely the result of the exclusion of the Senate from all
active participation in the government, and the fact that Rome retained
traditions of republican and senatorial rule incompatible with the spirit
of the new order. Yet, in spite of its loss of prestige, the Eternal City
continued to hold a privileged status, and its citizens were fed and
amused at the expense of the empire.

*The restoration of the frontiers.* The division of the military authority
among four able commanders enabled the government to deal energetically
with all frontier wars or internal revolts. In 296 Constantius recovered
Britain from Allectus,