Page:The American Cyclopædia (1879) Volume VI.djvu/127

 DIOCLETIAN ularity with the troops gave him the great- est influence. He held important positions under Probus and Aurelian, and served under Cams in the expedition against Per- sia, which was suddenly terminated by that emperor's death in his camp on the banks of the Tigris, in 284. When, during the retreat that followed, Numerian, the son of Carus, was assassinated, the soldiers unanimously chose Diocletian as his successor. But he was obliged to contest his position with Carinus, brother of Numerian, who was recognized as emperor in Europe. The armies of the hostile sovereigns met near Margum, not far from the Danube in Moesia, where the battle itself was decided against Diocletian ; but Carinus, eager- ly following the flying enemy, was killed by one of his own officers, and his army readily acknowledged Diocletian as his successor. He was installed as emperor with great ceremony at Nicomedia. But affairs were still in the greatest confusion, and he determined to asso- ciate with himself a colleague in the supreme dominion, and fixed his choice on Maximian, his old companion in arms, a rough barbarian, whom he invested with the imperial dignity in 286, and in whom he found a useful assistant and a constant friend. The Roman empire was beset with enemies and torn by factions. The peasants of Gaul rose in arms ; Mauritania was in rebellion ; Egypt was disturbed by external enemies and internal convulsions; while all along the frontier, from the Euphrates to the Rhine, the barbarians were threatening to de- stroy the empire by their invasions. Maximian subdued the BagaudaB or Gallic peasants, but Diocletian determined to strengthen the em- pire by raising two more Roman soldiers to the purple, Galerius, son of a Dacian shepherd, and Constantius, surnamed Chlorus, son of a noble Moesian, and father of Constantine the Great. These two princes in 292 received the title of Caesar, and having repudiate.d their wives, Galerius married the daughter of Diocle- tian, and Constantius the stepdaughter of Max- imian. Britain, Gaul, and Spain were assigned to Constantius ; Galerius received the Illyrian and Danubian provinces; Italy and Africa, with Sicily and the islands of the Tyrrhenian sea, were held by Maximian ; while Diocletian, the head of all, retained under his own domin- ion Thrace, Egypt, and the provinces of Asia, and established his capital at Nicomedia. By this arrangement, on the death of either of the Augusti, as Maximian and Diocletian were styled, the Csesar who had been associated with him was to be his successor, and another Csesar was to be appointed. These four princes, it was thought, would hold one another in check, so that no one of them would be able to attain to uncontrolled power. The plan was for a time successful. Maximian subdued the rebellious provinces of western Africa; Diocletian reduced and secured Egypt ; Gale- rius not only, under the superintendence of his father-in-law, compelled the Persians to make DIODATI 119 a treaty which secured the frontiers of that part of the empire for 40 years, but also vigi- lantly guarded the Danubian frontier ; while Constantius invaded Britain, which for several years had been detached from the rest of the empire under the rule of Carausius, and restored that island to the control of the Roman em- perors. After a prosperous reign of about 21 years, Diocletian, moved by his infirm health, or, as some writers have said, by the persua- sions or menaces of his son-in-law Galerius, voluntarily resigned the throne in 305, and re- tired to Salona in his native country, where he passed the remaining eight years of his life in retirement. Maximian, according to a pre- vious agreement, abdicated at the same time, but was not contented in a private station, and a few years later wrote to his former colleague, proposing to him to resume the reins of gov- ernment. The reply of Diocletian has become celebrated. "Would you could see," he said, "the cabbages planted by my hand at Salona; you would then never think of urging such an attempt." Diocletian struck a severe blow at the waning influence of the senate by the re- moval of his court from Rome to Nicomedia, reduced the numbers and the importance of the praatorian guards, divided the provinces so as to lessen the power of the provincial governors, and increased the dignity and ceremony with which the emperor was surrounded. He is censured for permitting the persecution of the Christians; but it must be remembered that the greater part of these persecutions took place after Diocletian had resigned his author- ity. The history of the reign of Diocletian is exceedingly confused, and only the principal events given above can be assumed to be ac- curate. Authorities differ widely in their ac- count of many of the details. The year 284, the period of Diocletian's accession, was made by the ecclesiastical writers the beginning of an era called " the era of Diocletian ;" a chro- nological form often employed in early theo- logical works. DIODATI, Domenieo, an Italian archaeologist and theologian, born in Naples in 1736, died there in 1801. He wrote several works on ecclesiastical history, and one on the coins of the Italian states ; but that by which he be- came widely known is entitled De Christo Greece loquente Exercitatio (Naples, 1767). The theory that Greek was the native language of the Jewish people in the time of Christ is advocated in this work with remarkable sub- tlety, nice comparison of passages, and a great variety of proofs, both external and internal. The academy della Crusca made him at once one of its associate members, and the empress of Russia sent him a gold medal for his service to the language of the sacred records. DIODATI, Giovanni, a Swiss theologian, born in Geneva in 1576, died there in 1649. His parents, natives of Lucca, had taken refuge in Switzerland from the persecution directed against them on account of their Protestant-