pre-Roman

Now I've got it stuck in my mind that it was about the same time as the Sassenach invasion of the South. Seems like the Britons invited the Angles and Saxons over to help them stave off the Picts. The Picts were certainly a problem because the Britons no longer had the Romans to defend them, but it may have been exacerbated by Scot pressure on the Picts.