Events By place Roman Empire Gladiatorial combat is outlawed in the Roman Empire. Constantine I personally assures the security of the Danube border by defeating the Goths, Vandals and Sarmatians. Asia Jin Cheng Di succeeds Jin Ming Di as emperor of China. By topic Art Constantine the Great, from the Basilica of Maxentius and Constantine, Rome, is started to be made. It is now kept at Palazzo dei Conservatori, Rome. Religion May 20—First Council of Nicaea—first "Ecumenical Council"… (More on 325)