Diocletian

Diocletian ruled from AD 284 to 305, ended fifty years of chaos, and was the first Roman emperor to abdicate voluntarily. Born around 244 in Dalmatia to a family of very low status — his father may have been a freedman — he rose through the army to command the imperial bodyguard, and was proclaimed emperor by the troops after Numerian's death. He inherited an empire that had seen roughly twenty-five emperors in fifty years, with invasion on every frontier, plague and a collapsed currency. His answer was to divide the job. He appointed Maximian as co-emperor in 286, and in 293 created the Tetrarchy: two senior Augusti and two junior Caesars, each with a region and a capital, with the Caesars intended to succeed after twenty years. Rome ceased to be an imperial residence. He doubled the army, separated civil from military authority, subdivided the provinces into about a hundred smaller units grouped into dioceses, and built a large bureaucracy. The Edict on Maximum Prices in 301 attempted to halt inflation by fixing the price of over a thousand goods on pain of death, and failed. He reformed the tax system onto a regular assessment of land and heads. He remade the emperor's person into something sacred — the title dominus, prostration, purple and jewels — modelled partly on Persian practice. From 303 he launched the Great Persecution, the most severe the church suffered: churches demolished, scriptures burned, clergy imprisoned, and sacrifice required on pain of death. He abdicated in 305 and retired to grow vegetables at Split, dying around 311 as the Tetrarchy collapsed.

• Lived: 244 CE – 311 CE
• Nationality: Croatian
• Roles: ruler, reformer