In the era of DNA analysis, we can get some amazing surprises.

Even what is white may be found to be black.

In fact, genetic evidence revealed Africans living amongst "indigenous" White British people for centuries. These "Black" British were of course unaware of their black ancestry.

The team at the University of Leicester discovered that one third of men with a rare Yorkshire surname possess a rare Y chromosome type which is typical for West African populations.

The African chromosome, called hgA1, was first found in a Leicester man, Mr. X, while the researchers were investigating a link between surnames and the Y chromosome, which come both from the father to the son. "As you can imagine, we were pretty amazed to find this result in someone unaware of having any African roots," explains Professor Mark Jobling, of the Department of Genetics at the University of Leicester. "The Y chromosome is passed down from father to son, so this suggested that Mr. X must have had African ancestry somewhere down the line. Our study suggests that this must have happened some time ago."

Most of Britain's one million "Black British" are immigrants from the Caribbean and Africa from the mid-twentieth century onwards, but they are not the first African people entering the islands.

In the second century they were first recorded in the Roman troops defending Hadrian's Wall. Six other men with the same surname, including an American whose ancestors had immigrated in the XIXth century, were carrying the hgA1 chromosome.

Genealogical investigation pointed to a common ancestor for all seven men 250 years ago, thus hgA1 Y chromosome is older than the one in their family. But the time when the first man carrying the gene entered Britain could not be established, and also if it was an African immigrant or a European male carrying an African Y chromosome. "This study shows that what it means to be British is complicated and always has been," says Professor Jobling.

"Human migration history is clearly very complex, particularly for an island nation such as ours, and this study further debunks the idea that there are simple and distinct populations or 'races'."

"Forensic scientists use DNA analysis to predict a person's ethnic origins, for example from hair or blood samples found at a crime scene. Whilst they are very likely to predict the correct ethnicity by using wider analysis of DNA other than the Y chromosome, finding this remarkable African chromosome would certainly have them scratching their heads for a while." said Jobbling.