* Divided the Roman empire into two halves, Eastern and Western, ruled by two emperors, or augusti.
* Each augustus would have a caesar, or junior emperor, to assist them.
* Created four administrative divisions, or prefectures, each ruled by a praetorian prefect.
* The prefectures were further divided into 12 dioceses, each ruled by a vicarius.
Economic Reforms
* Introduced a new tax system, the capitatio iugatio, which was based on the amount of land a person owned.
* Standardized the coinage system and introduced a new gold coin, the solidus, which became the standard currency of the empire.
Military Reforms
* Restructured the Roman army and created new units, including the limitanei (border troops) and the comitatenses (mobile field troops).
* Fortified the borders of the empire and built new forts and fortifications.
Religious Reforms
* Initiated the Diocletian Persecution, a series of edicts aimed at suppressing Christianity and other non-traditional religions in the empire.
* Promoted the traditional Roman gods and made it mandatory for all Roman citizens to make sacrifices to them.
Cultural and Artistic Reforms
* Built a new imperial palace in Split, Croatia, which was one of the largest and most luxurious palaces in the Roman world.
* Commissioned the construction of several public buildings and monuments, including the Baths of Diocletian in Rome.
* Patronized the arts and literature, and encouraged the revival of classical Greek and Roman culture.