Apart from a few short references in classical literature, knowledge of Britain before the Roman conquest (begun AD 43) is derived entirely from archaeological research. It is thus lacking in detail, for archaeology can rarely identify personalities, motives, or exact dates. All that is available is a picture of successive cultures and some knowledge of economic development. But even in Roman times Britain lay on the periphery of the civilized world, and Roman historians, for the most part, provide for that period only a framework into which the results of archaeological research can be fitted. Britain truly emerged into the light of history only after the Saxon settlements in the 5th century AD.