Ancient World
Diocletian and the Tetrarchy (293): Rule of Four Emperors
The Tetrarchy stabilised the empire after the third-century crisis, but the succession plan broke down soon after Diocletian abdicated in 305.
Region
Europe
Ancient World
Diocletian's Palace in Split: A Roman Emperor's Retirement Home
The palace housed the retired emperor and, from the 7th century, refugees from Salona, whose settlement grew into the city of Split.
Ancient World
Great Persecution (303-311): Diocletian Against the Christians
The persecution failed to suppress Christianity; Galerius ended it with an edict of toleration in 311, and it was finally abandoned in the East in 313.
Ancient World
Nydam Boat: Iron Age Ship from a Danish Bog Offering (c. 320)
The oldest known large clinker-built rowing ship of northern Europe, preserved in a bog as part of a war-booty offering.
Ancient World
Battle of the Milvian Bridge (312): Constantine's Victory
Constantine won decisively; Maxentius drowned in the Tiber and Constantine became sole ruler of the western Roman Empire.
Ancient World
Edict of Milan (313): Toleration for Christians in the Empire
Christians and all others gained legal freedom of worship, and property confiscated from the Church was ordered to be returned.
Ancient World
Arch of Constantine (315): Rome's Last Great Triumphal Arch
The Senate's arch celebrated Constantine's victory of 312 and survives as the largest and best-preserved Roman triumphal arch.
Ancient World
Founding of Constantinople (330): Constantine's New Rome
Constantine's new city became the main residence of the eastern emperors and, for over a thousand years, the capital of the Eastern Roman (Byzantine) Empire.
Ancient World
Wulfila's Gothic Bible: Christianity Among the Goths (c. 350)
The Goths gained a written language and a Bible in their own tongue, and Homoian ('Arian') Christianity spread among Germanic peoples.
Ancient World
Julian the Apostate (361-363): The Last Pagan Roman Emperor
Julian's attempt to revive traditional Greco-Roman religion ended with his death on campaign in Persia, and his successors restored Christianity's privileged position.
Ancient World
Arrival of the Huns in Europe (c. 370): Collapse of the Goths
The Alans and the Gothic kingdoms north of the Black Sea collapsed, and tens of thousands of Goths sought refuge inside the Roman Empire in 376.
Ancient World
Battle of Adrianople (378): Goths Defeat Emperor Valens
Decisive Gothic victory; Emperor Valens and roughly two-thirds of the eastern Roman field army were killed.