Around one million men in the UK can claim to be direct descendants of the Romans, scientists have revealed.
The Roman army invaded Britain in 43 AD and left around 400 years later, in the early 5th century. But historians and scientists claim that the legions left behind their legacy in the genes of many Britons.
A study by BritainsDNA, a commercial DNA testing company, compared Y chromosome markers found in men in Britain with those found in modern Italy. The results found five major types of DNA which were likely to have come from the Roman legions.
The first, known as Alpine, was found in 13% of Italian men, 6.5% of men in England and Wales, 4.3% in Scotland and 1.8% in Ireland.
As Ireland was never conquered and Scotland was only occupied for a short time, the researchers said these figures suggested this DNA was a "probable candidate" to be linked to the Romans.
When applied to the total population of the UK, it was estimated that 1.6 million men carried the Alpine marker, of which half a million may be descended from the Roman armies.
When the researchers included the four further markers - known as Balkan, Ancient Caucasians, Herdsmen-Farmers and Anatolian - they calculated that at least one million British men may be direct descendants of the Romans.
The study concluded: "Since the number of Italians or descendants of Italians in the legions did reduce very much over time, we estimate conservatively that one million men in Britain descend from Romans in the direct male line.
"What this fascinating piece of research shows is that the Romans did indeed do something for us, for about a million of us in fact."
The results of the research, carried out by Alistair Moffat, historian and BritainsDNA managing director, and Dr Jim Wilson, BritainsDNA chief scientist, will be discussed at the Who Do You Think You Are? Live family history event at Olympia, in London.