- Roman Emperor AD 284-305.
Gaius Aurelius Valerius Diocletianus was commander of the Imperial Guard and became emperor when Numerian (AD 283-4) was assassinated. He was the last reigning Roman emperor to visit Egypt: he was present at the fall of Alexandria after a siege of eight months, and then journeyed south. He withdrew the southern Egyptian border from Nubia and re-established it near Philae in c.AD 298; the Roman Town Gate at the north-east end of the island of Philae probably dates from this time. On his return northwards, he and his entourage stayed at Panopolis and in AD 302, he was in Alexandria shortly before the persecution of the Christians occurred. They hated him for his role in inaugurating this suffering which continued for at least another ten years. He chose Jupiter as his own patron god and, throughout his long and stable reign, he sought to re-introduce traditional beliefs and ideas.In Egypt, the reign of Diocletian is regarded as the watershed between the Roman and Byzantine periods. He made several important economic changes relating to the Egyptian taxation and monetary systems: in AD 296, the coinage was officially revalued and it was no longer permitted to remain separate from the coinage in the rest of the Roman Empire, while an attempt was also made to fix a maximum price for all goods and services.BIBL. Jones, A.H.M. The Later Roman Empire 284-602. Oxford: 1964.Biographical Dictionary of Ancient Egypt by Rosalie and Antony E. David* * *(reigned 284–305 AD)Roman emperor. Original name Diocles. Full name Gaius Aurelius Valerius Diocletianus. Born in Dalmatia on 22 December 243/245, he joined the army and rose to the rank of commander of the Royal Bodyguard. Upon the mysterious death of the Emperor Numerian, he was proclaimed emperor on 20 November 284. In a series of campaigns, Diocletian reunited the empire under his rule. In 298, he crushed the revolt of Lucius DomitiusDomitianusin Alexandria. Diocletian reorganized the empire and instituted the system of two emperors with a Caesar to assist each. He also undertook the systematic persecution of Christians in an attempt to restore old Roman values. Diocletian abdicated on 1 May 305 and retired to Salonae, where he saw the empire relapse into civil war among his successors. He died in Salonae on 3 December 316 or possibly 311.See also Galerius Valerius Maximianus, Caius.Historical Dictionary Of Ancient Egypt by Morris L. Bierbrier
Ancient Egypt. A Reference Guide. EdwART. 2011.