Ancient DNA extracted from skeletons in burial sites across England has revealed where the first people to call themselves English originally came from.
The research, published in Current Archaeology, has found they largely descended from northern Europeans, mainly Germany, Denmark and the Netherlands.
The findings have also challenged perceptions that English ancestors lived in small elite groups.
Evidence collected during the study suggests there was actually mass migration from Europe and the movement of people from as far as West Africa in the Middle Ages, archaeologists have said.
"This reminds us that our past isn't this little quaint village where everybody dances around a maypole," said Professor Duncan Sayer, project leader and archaeologist from the University of Central Lancashire.
"The research is a breakthrough: it challenges our perceptions and understanding of ancient England, showing how pivotal migration is to who we are, and for the first time allows us to explore community histories in new ways."
The discoveries come from one of the largest ancient DNA projects in Europe, involving 460 people buried in graves between 200AD and 1300AD, with more than half from England.
The Updown Girl discovery
While the DNA analysis revealed significant population changes across the country in the Middle Ages, it also shed light on "striking" individual stories of those buried.
One of which was that of a young girl buried in Kent in the early 7th Century, researchers said.
Nicknamed Updown Girl, because she was found near a farm in Eastry with the same name, she was 10 or 11 years old when she died, the study found.
Buried alongside typical grave goods such as a pot, a bone comb and a knife, DNA analysis showed she descended of West African heritage on her father's side, researchers said.
Based on how she was buried, the archaeologists said it was likely that she was treated the same as other family members, despite her different ancestry.
Two women of Northern European descent, likely to be the girl's great aunts, were found buried similarly nearby.
"We found the granddaughter of a migrant who is part of a family that is biologically Northern European," Prof Sayer added.
"She is buried in exactly the same way as everybody else... this story really highlights that if we are looking at ethnicity, it did not matter to these people."
What other discoveries were made?
Other notable findings included the remains of a teenage boy in an early medieval cemetery in Yorkshire, with 100% Northern European ancestry.
He was buried with an armed brooch - an object that originated from Scandinavia.
At a cemetery near RAF Lakenheath, in East Anglia, a double grave containing a 15-year-old boy and a 12-year-old girl was found.
They were buried alongside a knife and a buckle, and the remains of their father were found nearby, buried with a spear, knife and pottery sherd.
"Our work shows that this migration cannot be understood as one single event; rather, it's made up of many different threads - of individual people and families adapting to new circumstances across the regions of Britain," Prof Sayer said.
"It is amazing being able to weave those threads together to create the fabric of their stories and, in doing so, the rich and complex tapestry of our own past."