My surname is considered quite English, and has been regarded as a “place” name, associated with the hill forts mentioned in the article, that are scattered across England and Wales. But, I’ve found that there actually are ancient, Irish beginnings, with the name arising from one of the territorial “warrior kings” of Ireland, named O’Tuathail, killed and buried at Glendalough, County Wicklow, in the ninth century. The name first showed up in England in the Templar Inquisition of 1185. Then, the surname turns back up in Ireland during the Cromwell era, and a fair number remain there to this day. I’ve yet to have my DNA done, to see what the genetics say about all this, though.
You’re likely an R1b like myself and 90% of the Irish.