The DNA ancestry project says:
Niall Noigiallach aka "Niall of the Nine Hostages" (d450/455 ad.) was 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.
A blog post at Sandwalk about Niall contained a drawing and a map.
This site gave the Niall of the Nine Hostages a modern day twist:
Harvard Prof. Henry Louis Gates Jr., who made headlines when he was arrested by an Irish police officer while trying to break into his own locked home, is also a descendant of Niall of the Nine Hostages — and is related to the cop who booked him!
After reading what little I have about Niall, it may be more amazing to have Great Britain roots and not be Niall's descendant!
Disclaimer: This was posted just for fun. I do not know what evidence exists to link James Grear/Greer of Gunpowder River to Niall. Obviously my 10 minutes of Google research does not constitute thorough research on this potential ancestor!