Diocletian, dl-o-kle'she-an, [Lat. Diocletia'nus ;
Fr. Diocletien, de'o'kla'te^aV,] or, more fully, Cai'ua
Vale'rius Aure'ljus Diocletia'nus, a Roman emperor,
was born of obscure parents at Dioclea, in Dalmatiaabout 245
A.D. He entered the army young, served under
Aurelian, and obtained a high command under Probus.
He accompanied Carus in his expedition against Persia,
and at the death of that prince, in 283, he became commander
of the imperial guards of his successor, Niimerianus.
The latter having been assassinated by Aper,
the army at Chalcedon proclaimed Diocletian emperor
in 284. In 286 he adopted Maximian as his colleague
in the empire, and gave him the title of Augustus. They
were successful in suppressing revolts in Gaul and other
parts of the empire. About 292 they nominated two
Csesars to divide the labours of the administration,-
namely, Galerius and Constantius Chlorus. Diocletian
reserved to himself Asia and Egypt, and fixed his court
at Nicomedia. He assigned Italy and Africa to Maximian,
Gaul and Spain to Constantius, and Thrace and
lllyricum to Galerius. The supremacy of Diocletian
was recognized by the other three, and general prosperity
resulted from this arrangement. One design of
this policy was to prevent the revolt of the armies in
favour of their commanders, by which so many emperors
had been ruined. After this division the Roman arms
were successful in Egypt, Persia, and Britain. In 297 a
peace was made with Persia, which was maintained forty
years. The Christians had enjoyed the favour and protection
of Diocletian ; but in 303 Galerius, by false accusations,
persuaded him to issue an edict against them.
This persecution, to which he unwillingly assented, is
the chief error of a reign otherwise honourable and
happy. In 304 he had a long attack of sickness, and
in the next year he abdicated in favour of Galerius, and
retired to Salona, where he turned his attention to the
cultivation of a vegetable-garden, and died in 313. His
political talents were superior, and entitle him to a place
among the most eminent Roman emperors.
See Tillemont, "Histoiredes Empereurs:" Gibbon, "Decline
and Fall of the Roman Empire;" Ai'kelius Victor, "De
;" J. C. Sickel, "Dioclelianus et Maximums," 1792.
Gaius Aurelius Valerius Diocletianus[notes 1] (c. 22
December 244 – 3 December 311), commonly known as
Diocletian, was a Roman Emperor from 284 to 305.
Born to an Illyrian family of low status in the Roman
province of Dalmatia, Diocletian rose through the ranks of
the military to become cavalry commander to the emperor
Carus. After the deaths of Carus and his son Numerian on
campaign in Persia, Diocletian was acclaimed emperor. The
title was also claimed by Carus' other surviving son,
Carinus, but Diocletian defeated him in the Battle of the
Margus. With his accession to power, Diocletian ended the
Crisis of the Third Century. He appointed fellow-officer
Maximian Augustus, his senior co-emperor, in 285. He
delegated further on 1 March 293, appointing Galerius and
Constantius as Caesars, junior co-emperors. Under this
"Tetrarchy", or "rule of four", each emperor would rule over
a quarter-division of the empire. Diocletian secured the
empire's borders and purged it of all threats to his power.
He defeated the Sarmatians and Carpi during several
campaigns between 285 and 299, the Alamanni in 288, and
usurpers in Egypt between 297 and 298. Galerius, aided by
Diocletian, campaigned successfully against Sassanid Persia,
the empire's traditional enemy. In 299 he sacked their
capital Ctesiphon - Diocletian led the subsequent
negotiations and achieved a lasting and favorable peace.
Diocletian separated and enlarged the empire's civil and
military services and reorganised the empire's provincial
divisions, establishing the largest and most bureaucratic
government in the history of the empire. He established new
administrative centers in Nicomedia, Mediolanum, Antioch,
and Trier, closer to the empire's frontiers than the
traditional capital at Rome had been. Building on third-
century trends towards absolutism, he styled himself an
autocrat, elevating himself above the empire's masses with
imposing forms of court ceremonial and architecture.
Bureaucratic and military growth, constant campaigning, and
construction projects increased the state's expenditures and
necessitated a comprehensive tax reform. From at least 297
on, imperial taxation was standardized, made more equitable,
and levied at generally higher rates...