Media playback is unsupported on your device Media caption Dr Rebecca Redfern of the Museum of London talks about the bones of a teenager who was living in London 2,000 years ago

A DNA study has confirmed that London was an ethnically diverse city from its very beginnings, BBC News has learned.

The analysis reveals what some of the very first Londoners looked like and where they came from.

These initial results come from four people: two had origins from outside Europe, another was from continental Europe and one was a native Briton.

The researchers plan to analyse more of the 20,000 human remains stored at the Museum of London.

According to Caroline McDonald, who is a senior curator at the museum, London was a cosmopolitan city from the moment it was created following the Roman invasion 2,000 years ago.

Image copyright Museum of London, Peter Jackson Image caption Early London: An artist's impression of building work at the Roman Fort Wall in AD 200

"The thing to remember with the original Londoners is that they were not born here. Every first-generation Londoner was from somewhere else - whether it was somewhere else in Britain, somewhere else on the continent, somewhere else in the Mediterranean, somewhere else from Africa," she said.

"So the stories we can tell about our ancient population are absolutely relevant to modern contemporary London because these are our stories - these are people just like us."

Working with scientists at Durham University and an ancient DNA lab at McMaster University in Canada, museum researchers were able to reconstruct the DNA of four individuals.

They come from a collection of 20,000 human remains from London stretching back 5,500 years.

Each of these individuals are stored in their own cardboard box in a storehouse at the museum. The development of DNA analysis techniques now means that "flesh can be put on the bones" of the history of these Londoners: telling us where they came from, how they lived and how they died.

Further analyses will greatly add to our knowledge of the history of the city and enable researchers to view events through the eyes of people that lived in it at the time, according to Ms McDonald.

"Their stories are written in their bones and these were stories we did not realise until we did this scientific analysis," she told BBC News.

The Lant Street teenager

The most complete skeleton studied was that of a 14-year-old girl, who the museum curators have named "The Lant Street teenager". Analysis of her DNA and chemicals in her teeth show that she grew up in North Africa. Her mitochondrial DNA lineage (passed down on the maternal line only) is common in southern and Eastern Europe.

The teenager had blue eyes and yet there were things about her skeleton that suggested some she had Sub-Saharan African ancestry. Like many people living in the capital today, she had travelled a long distance to be in London.

The Mansell Street man

Archaeologists build up a picture of individuals from the belongings they are buried with. But "The Mansell Street man" was found with nothing. According to Dr Rebecca Redfern, another Museum of London curator, until the emergence of new ancient DNA and chemical analysis techniques, these were the people who had slipped through the cracks of history.

"Most of the human remains in our collection don't have any coffin plates or any sort of biographical information, so by doing these types of studies we are able to show where people came from and learn more about them as a person, about aspects of their physical appearance, and so we can really give people back their voices," she said.

The analysis showed that Mansell Street man was over 45 years old with very dark brown hair and brown eyes. His mitochondrial DNA line was from North Africa and his remains show African traits as well.

However, the chemical make-up of his teeth shows he grew up in London. His skeleton indicates that he had a form of bone disease that today is associated with diabetes caused by a protein-rich diet. That has come as a huge surprise to researchers because in modern populations this is a disease that mostly afflicts white males from the West. So the discovery will be of great interest to medical researchers.

The Gladiator

This man was possibly a gladiator. His skull was found in a pit along with the heads of 38 other men aged between 18 and 45 - all of whom had met a violent end. This particular individual was 36-45 when he died.

He had suffered serious injuries to his skull that had healed, so he had led a violent life up to his death.

His mother's ancestral line is common in Eastern Europe and the Middle East. The Gladiator was not born in London, but he met a tragic end in the city. His head was removed from his body and probably left exposed in these pits for passers-by to see.

The Harper Road woman

"The Harper Road" woman was a first-generation Londoner. She had brown hair and brown eyes and died a handful of years after the city had been settled - shortly after Britain had been invaded by the Roman Empire in AD 43.

She is buried with Roman pottery and belongings. When researchers checked the chemicals in her teeth, they confirmed she had been born in Britain. Ms McDonald was intrigued by the fact that a native Briton adopted a Roman lifestyle within a few years of the conquest.

"What this is telling us is that people's identities were very, very fluid... her family wanted to portray a certain Roman style of identity. The Harper Road woman would have adapted her identity depending on who she was meeting - the way that we all do," she said.

An added twist to the Harper Road woman's tale is that her chromosomes show that she was genetically a male - even though physically she was a woman - another feature that will intrigue modern-day researchers.

Waiting in the wings are thousands more people in the Museum of London's store house that the researchers are eager to learn more about.

Next on their list are more Roman Londoners, then a group of Napoleonic soldiers and marines that were buried in Greenwich, followed by a group of medieval monks.

"We would like to do an awful lot more because everyone has their own story to tell - so the more people we are able to analyse the more stories we can tell about London," says Dr Redfern.

The research, and skeletons used for analysis will form a new display at the Museum of London opening on 27 November 2015.

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