Diocletian was Emperor of Rome from A.D. 284-305. He attempted to destroy the Christian faith by burning the scriptures. He also forbade worship and arrested clergy. He insisted on pagan sacrifices. He martyred hundreds of Christians from Europe to North Africa.
Diocletian attempted to save the Roman empire by dividing it into eastern and western regions, with Byzantium as the capital of the East and Rome as the capital of the West. He established the "tetrarchy", or division of power among four rulers in 293 A.D. The tetrarchy included two primary rulers, each with the title "Augustus", who ruled over the eastern and western empires, and two "Caesars" who served under the Augustuses. He imposed economic regulations, some of which seem silly today. For example, Diocletian required farmers to stay with their land and workers to stay on the job for the rest of their lives. He did this to prevent people from leaving their work to avoid taxation. For an empire that embraced slavery, this probably seemed like normal regulations. Diocletian also imposed wage and price controls to halt inflation. That economic regulation, which almost always fails, is still attempted by modern rulers, such as the United States President during World War II and even President Richard Nixon in the early 1970s.
Diocletian also attempted to suppress Christianity by ordering Christians to worship him and brutally persecuting them when they did not. He was the last emperor to do this. Diocletian abdicated due to a stomach illness in A.D. 305. He lived long enough to see that the system that he set up for orderly succession had failed as open warfare broke out soon after he gave up power.