The End of Roman York
Eboracum (Roman York) remained an important provincial capital throughout the 4th century but by the turn of the 5th century it was virtually abandoned.
It's not clear whether the Sixth Legion were permanently garrisoned in York, although there is evidence from a late Roman military document (the Notitia Dignitatum) that the city was still its base. The same document suggests that the city was home to the Dux Britannarium (Duke of the Britains) who appears to have been in charge of all forces in the north.
It must have been a difficult time. There was a barbarian attack on Roman Britain in 367 which Roman forces were unable to repel. The emperor at the time had to send a high ranking official to restore Britain's defences.
It's clear that the 4th century also saw a decline in York's economy - the population shrinks, trade declines, buildings are abandoned and the streets are poorly maintained. That said, there is some new work - defensive ditches are re-dug and at least one new defensive tower - known as the Anglian Tower - is thought to have been built in this period.
By the end of the century the Roman empire is on the point of collapse and soon after 400 AD the Roman Army is forced to abandon Britain; York is deserted as a military base.