Irish High King Niall
In February 2006, researchers at Trinity College in Dublin released a paper that studied that Y chromosome signature of men throughout Ireland. They found that 8% of men sampled had the same Y chromosome, with a cluster in the northwest where fully 21% of men carried the signature chromosome (which fell into Haplogroup R1b1c7). The article appeared in The American Journal of Human Genetics and was titled “A Y-Chromosome Signature of Hegemony in Gaelic Ireland.”
The researchers looked at 17 STR markers on Irish Y chromosomes to determine the relatedness of samples they had obtained. They found that there was a strong association between the most common signature and surnames that were related to the most significant dynasty of early medieval Ireland – the Ui Neill. Some of the surnames included McCaul, McGovern, McLoughlin, McManus, McMenamin and Molloy (list from Oxford Ancestors). Of course there were no surnames at the time of the earliest Ui Neill dynasty, but when the Irish took surnames around 1,000 A.D., many chose names that were associated with Ui Neill dynasties.
This association suggests that men with the signature Y chromosome are descended from the founder of the dynasty Ui Neill, Niall of the Nine Hostages. Niall of the Nine Hostages, who was the High King at Tara from 379 to 405, founded the dynasty Ui Neill, which ruled until the 11th century. Niall is considered one of the greatest Irish kings. He was said to have consolidated his power by leading raids on the Roman Empire, taking hostages from rival Irish royal families, Britain and the European mainland, thus earning the name Niall of the Nine Hostages. Saint Patrick was said to have been kidnapped and brought to Ireland as one of his hostages during his raids.
According to the legend, Niall had 12 sons, many of which were rulers after Niall’s death. The first notice of the Territory of Feara Ceall which occurs in the Annals of the Four Masters is at the year 839, when it is recorded that it was plundered by the King, Niall Caille, and henceforwards we find it in the possession of the O'Molloys, the descendants of Fiacha, the son of Niall of the Nine Hostages.