- Became ruler in 284 A.D.
- Divided empire into two parts; EAST and WEST
- He controlled eastern half which included man important cities/areas in Egypt, Greece, and Western Asia
- Issued new coins (currency), which incresed trade
- Persecuted (punished) Christians
- Retired in 305 A.D.
- Tried to reunite empire, but gave up and concentrated on the east
- Moved capital to Byzantium - Constantinople (modern day Istanbul)
- Constantinople is/was located in Asia and Europe and sat on a peninsula
- Built public baths, aqueducts, libraries
- Helped Christians by building churches and giving leaders jobs
- Persecuted non-believers and non-Christians
- Tried to take back land in Africa/Europe that was lost to Germanic people for example
- Built Hagia Sophia Church
- Believed strongly in Roman laws/traditions
- Advisers to the emperor created a set of "Justian Laws/Codes"
- Worked closely with wife Theodora
- Built up city making it a great city