The history of the island was written in the eighth century C.E. by an English monk named Bede, who said Rome's decline in about 400 C.E. led to an invasion from the east. The natives of the island became terrible to the Jute tribes because they became so large.

Many archaeologists suspected that Bede had overstated the invasion's scale. They imagined a small migration of a warrior elite who imposed their culture on the population. Bede may have been at least partly right according to a new study. More than half of the people who died in England between 400 and 900 C.E. were descended from Northern Europe.

The debate about whether past cultural change signals new people moving in or a largely unchanged population adopting new technologies has been going on for a long time. Catherine Hills, who was not part of the research, said that the data pointed to migration. The new data shows a lot of movement into the British Isles.

Archaeologists found the outlines of Bede's tale when they excavated Anglo-Saxon houses and burials. Around 450 C.E. in western England, Roman-style pottery, tools, and architecture dwindled; jewelry, swords, and houses started to resemble those found along the North Sea coast in what is today Germany and the Netherlands. The helmets and weapons of the new land are stunning.

The material culture of Roman Britain was very different from that of Anglo-Saxon Britain. The idea of migration has been rejected by most archaeologists as an overly simplistic explanation for cultural change.

The new analysis brings it back to life. A rapid, large-scale migration from Northern Europe began by 450 C.E., according to samples from more than 20 cemeteries along England's eastern coast. The co-author of the book says that some Anglo- Saxon sites look like continental European. There is a large amount of people coming in from the North Sea.

Archaeologists excavate a woman buried with a cow
A woman buried with jewelry and a whole cow had predominantly local DNA, suggesting immigration and status weren’t linked in the Anglo-Saxon period.Duncan Sayer

Huge cultural changes came from the population shift. The period of language change was dramatic. Old English is a Germanic language that is similar to German and Dutch. There is a lot of Germanic speakers in Britain.

The Vikings who came to the North Sea a few centuries later left fewer traces than the Anglo-Saxons.

Bede did get it right. The graves don't tell the whole story. People with little continental DNA were buried in Anglo-Saxon fashion. The results show that both women and men are immigrants.

Intermarriage and integration lasted for centuries, as the team found many people had a mixture of continental Europe and eastern Great Britain's genes. A woman in her 20s with mixed ancestry was laid to rest under a mound with silvered jewelry, amber beads, and a cow. Co-author Duncan Sayer said that the evidence suggests more complexity than simple conquest. He says that the invasion hypothesis is a million miles away.

Mass immigration is linked to family relationships within the cemetery. Three generations of people with the same genetic makeup were buried together. In line with evidence in northern Germany of settlements coming to sudden ends in the fifth or sixth centuries C.E., Sayer thinks there are families moving.

Descendants of people buried on the continent may move back and forth between Great Britain and Ireland. The results show that Great Britain is not an isolated island as was thought. People used to come and go on the North Sea. Mobility may be more normal than we think.