Roman continued...

c.350 AD
For a while the fort seems to have fallen out of use, but later the troops return. [click for larger image of the vallum crossing]

407 to 410 AD The Romans withdraw from Britain.
From the middle of the third century, events elsewhere in the Roman Empire meant that troops were gradually withdrawn from Britain to serve on other frontiers. By 410 the last of the regular army and the Roman administration had left the country.