The settlement of Great Britain by Germanic peoples from continental Europe led to the development of an Anglo-Saxon cultural identity and a shared Germanic language—Old English—whose closest known relative is Old Frisian, spoken on the other side of the North Sea. The first Germanic speakers to settle in Britain permanently are likely to have been soldiers recruited by the Roman administration in the 4th century AD, or even earlier. In the early 5th century, during the end of Roman rule in Britain and the breakdown of the Roman economy, larger numbers arrived, and their impact upon local culture and politics increased.
There is ongoing debate about the scale, timing and nature of the Anglo-Saxon settlements and also about what happened to the existing populations of the regions where the migrants settled. The available evidence includes a small number of medieval texts which emphasize Saxon settlement and violence in the 5th century but do not give many clear or reliable details. Linguistic, archaeological and genetic information have played an increasing role in attempts to better understand what happened. The British Celtic and Latin languages spoken in Britain before Germanic speakers migrated there had very little impact on Old English vocabulary. According to many scholars, this suggests that a large number of Germanic speakers became important relatively suddenly. On the basis of such evidence it has even been argued that large parts of what is now England were clear of prior inhabitants, perhaps due to mass deaths from the Plague of Justinian. However, a contrasting view that gained support in the late 20th century suggests that the migration involved relatively few individuals, possibly centred on a warrior elite, who popularized a non-Roman identity after the downfall of Roman institutions. This hypothesis suggests a large-scale acculturation of natives to the incomers' language and material culture. In support of this, archaeologists have found that, despite evidence of violent disruption, settlement patterns and land use show many continuities with the Romano-British past, despite profound changes in material culture.
