CAESAR VALERIUS JOVIVS, a celebrated Roman emperor, born of an obscure family in Dalmatia in the year 245. Although originally a common soldier, yet by merit and success he gradually rose to the rank of general; and at the death of Numerian in 284 he was invested with the imperial purple. In this high station he rewarded the virtues and fidelity of Maximian, who had shared with him all the subordinate offices in the army, by making him his colleague on the throne. He created two subordinate emperors, Constantius and Galerius, whom he called Caesars, whilst he claimed for himself and his colleague the superior title of Augustus. Diocletian has been celebrated for his military virtues; and although he was naturally unpolished by education and study, yet he was the friend and patron of learning and true genius. He was bold and resolute, active and diligent, and well acquainted with the arts, which endear a sovereign to his people, and make him respectable even in the eyes of his enemies. His cruelty, however, against the followers of Christianity, has been deservedly branded with infamy. After he had reigned twenty-two years in the greatest prosperity, he publicly abdicated the crown at Nicomedia in 305, and retired to a private station at Salona. Maximian his colleague followed his example, but not from choice; and when he some time afterwards endeavoured to rouse the ambition of Diocletian, and to persuade him to re-assume the purple, he received for answer, that Diocletian took now more delight in cultivating his little garden than he had formerly enjoyed in a palace, when his power extended over all the Roman world. He lived nine years after his abdication, in the greatest security and enjoyment, at Salona, and died in 314, in the sixty-eighth year of his age. Diocletian is the first sovereign who voluntarily resigned his power. His bloody persecution of the Christians forms a chronological era, called the era of Diocletian, or of the martyrs. It was for a long time in use in theological writings, and is still preserved by the Copts and Abyssinians. It commenced on the 29th August 284.