Scientists in Ireland may have found the country’s most fertile male, with more than 3 million men worldwide among his offspring.

The scientists, from Trinity College Dublin, have discovered that as many as one in twelve Irish men could be descended from Niall of the Nine Hostages, a 5th-century warlord who was head of the most powerful dynasty in ancient Ireland.

His genetic legacy is almost as impressive as Genghis Khan, the Mongol emperor who conquered most of Asia in the 13th century and has nearly 16 million descendants, said Dan Bradley, who supervised the research.

“It’s another link between profligacy and power,” Bradley told Reuters. “We’re the first generation on the planet where if you’re successful you don’t (always) have more children.”

The research was carried out by PhD student Laoise Moore, at the Smurfit Institute of Genetics at Trinity. Moore, testing the Y chromosome which is passed on from fathers to sons, examined DNA samples from 800 males across Ireland.

The results - which have been published in the American Journal of Human Genetics - showed the highest concentration of related males in northwest Ireland, where one in five males had the same Y chromosome.

Bradley said the results reminded the team of a similar study in central Asia, where scientists found 8 percent of men with the same Y chromosome. Subsequent studies found they shared the same chromosome as the dynasty linked to Genghis Khan.

GENGHIS KHAN EFFECT

“It made us wonder if there could be some sort of Genghis Khan effect in Ireland and the best candidate for it was Niall,” Bradley said.

His team then consulted with genealogical experts who provided them with a contemporary list of people with surnames that are genealogically linked to the last known relative of the “Ui Neill” dynasty, which literally means descendants of Niall.

The results showed the new group had the same chromosome as those in the original sample, proving a link between them and the Niall descendents.

“The frequency (of the Y chromosome) was significantly higher in that genealogical group than any other group we tested,” said Bradley, whose surname is also linked to the medieval warlord. Other modern surnames tracing their ancestry to Niall include Gallagher, Boyle, O’Donnell and O’Doherty.

For added proof, the scientists used special techniques to age the Y chromosome, according to how many mutations had occurred in the genetic material over time. The number of mutations was found to be in accordance with chromosomes that would date back to the last known living relative of Niall.

Niall reportedly had 12 sons, many of whom became powerful Irish kings themselves. But because he lived in the 5th century, there have been doubts the king - who is said to have brought the country’s patron saint, Patrick, to Ireland - even existed.

“Before I would have said that characters like Niall were almost mythological, like King Arthur, but this actually puts flesh on the bones,” Bradley said.

When international databases were checked, the chromosome also turned up in roughly 2 percent of all male New Yorkers.