245 - 313 AD
In 245 AD
the wily, subtle Diocletian had become ruler of the whole empire. His reorganization of its government was so extensive that historians call the period from 245 AD onward the Late Roman Empire. Essentially, Diocletian consolidated the tremendous alterations which had been required to cope with the stress of the 3rd century. Politically his subjects had to yield their local self-government and individual freedom to the demands of an all-powerful central administration and its agents. In order to protect his Empire from its external dangers, the emperor had created a mobile field army which made more use of cavalry than had been true in the days of Augustus and Hadrian.
To secure the funds for this elaborate and expensive structure of government, Diocletian reorganized the tax system of the empire and restored order to the currency. Diocletian was present at the fall of Alexandria after a siege of eight months. After the capitulation, Diocletian is alleged to have vowed to continue the slaughter of the populace until the blood reached his horse's knees. After the siege of Alexandria, Diocletian traveled up-river to the southern frontier.
The trip to the border appears to have had a serious military and political aim for Diocletian as he re-established and refortified the island of Philae as a frontier post and came to an accommodation with the tribes which inhabited the border region. Years later, Diocletian was in Alexandria again, just before the beginning of the "Great Persecution" of the Christians. He was so detested by Egyptian Christians for this that the Church later dated its "Era of Martyrs" retrospectively from the first year of his reign. Diocletian also ordered against the practice of the Persian religion in the Roman empire at this time and this may well be another aspect of a general desire to re-establish the strength of the traditional Roman religion. Diocletian was the last reigning Roman emperor to visit Egypt.