4th century in Roman Britain
Events from the 4th century in Roman Britain
Emperor Diocletian fixes the prices of British woollen goods and beer.
25 July – Emperor Constantius Chlorus dies at Eboracum (York), after campaigning against the Picts. His son Constantine the Great is acclaimed as his successor by the troops here.
The reforms of Diocletian take effect, dividing Britain into four provinces and separating military and civilian government.
Establishment of initial Christian hierarchy in Britain.
Three British bishops attend the Council of Arles.
January – Emperor Constans visits Britain, and strengthens northern frontier and Saxon Shore.
Construction of Pevensey Fort.
Roman Emperor Constantius II punishes British supporters of the recently defeated usurper, Magnentius, and suppresses paganism.
Julian the Apostate placed in charge of Britain and Gaul.
Julian makes Britain main granary for western Roman army.
Picts and Irish attack northern frontier.
The Great Conspiracy: Sustained raids by Picts, Irish, and Saxons. Hadrian's Wall abandoned and military commander Fullofaudes captured or killed.
Count Theodosius arrives in Britain with a military task-force, restores administration under Governor Civilis and commander Dulcitius.
Theodosius defeats invaders, builds new watchtowers from Filey to Huntcliff, re-fortifies northern frontier.
Magnus Maximus defeats the Picts and Scots.
Maximus usurps control of the Empire, taking troops from Britain and abandoning the forts at Chester and the Pennines.
Saint Ninian converts the region around Galloway to Christianity.