The Roman historian Tacitus suggested that the Britons were descended from people who had arrived from the continent, comparing the Caledonians (in modern-day Scotland) to their Germanic neighbours; the Silures of Southern Wales to Iberian settlers; and the inhabitants of Southeast Britannia to Gaulish tribes [REF].
From the early 20th century, this "invasionist" scenario was juxtaposed to a diffusionist view.