I guess that most of us learned in school that the Romans ditched Britain in 410 AD and abruptly left us to our own devices to run off to protect Rome from the marauding Visigoths. There are many myths about the Roman withdrawal: from the date and ramifications of the withdrawal of troops (was it a sudden departure or a gradual leaving?), to the state of Britain in its wake (did it totally collapse without the Romans to keep us in order or was there an amount of continuity?).
So, firstly, did the Romans really abandon Britain in 410? That has long been the date we assume the Romans left Britain, summoned back by Honorius to defend Rome. Traditionalists have believed that the Romans abandoned their villas, their culture, and left en masse, for the ignorant Britons and Celts to allow civilisation to go to rack and ruin.
Now a different view is emerging. It appears (eg from studies of Notitia Dignitatum 4th/5th c AD) that Roman military units were still here much later, suggesting a gradual withdrawal over possibly half a century, and even the ‘Honorius edict’ is in dispute. We only have ‘evidence’ written in the 6th ,7th and 8th centuries either by Byzantine officials or writers such as Gildas, Bede and Nennius, who are now regarded by many academics as distant from events, subjective and unreliable.
Did many of the Romans from the occupation remain in Britain, in their military units, intermarrying with Britons and Celts, becoming integrated and merging cultures? I’d like to think so, although that raises a few more questions …