found this on the internet.....seems to indicate that the term Black Irsih means quite different things to different people, and has no actual definition; The Black Irish seem to be mainly a U.S. thing. The Irish natives I've heard from say the term is new to them. People talk about the Black Irish as though they constituted a mythical race on a par with the lost tribes of Israel. But in fact all they mean (usually) is that somebody named McNulty has dark, and in the classic case black, hair. Even if we make the dubious assumption that dark hair genes were completely absent in the original Gaels, it seems likely that the incidence of dark-haired folk in a nation whose population only slightly exceeds that of the city of Los Angeles could be accounted for strictly by routine mixing due to immigration, trade contact, and so on. But you can see how exciting an explanation that makes. So people have come up with all kinds of fanciful tales instead. The wildest notion is that black hair is evidence of Spaniards marooned in Ireland following the wreck of the Armada. As we've had occasion to discuss in the past, the number of shipwrecked Spanish sailors who remained in Ireland for any length of time was trivial. I have also heard it said the black Irish were the first settlers of Ireland--maybe the Phoenicians. The red Irish, meanwhile, were descendants of the Normans, and the blond Irish are descended from the Vikings. One of many drawbacks to this theory is that it seems to leave the Gaels completely out of the picture. A more plausible but still essentially unprovable take on this idea is that black hair is a vestige of an indigenous population of short dark-haired types overrun by the fair-haired Gaels. Supposedly there are more black Irish in the western part of the country, which fewer Gaelic invaders reached. Other theories indicate a mix with the black race, and others think that an infusion of American Indian blood is the basis of the term. There is archaeological and, I'm told, linguistic evidence of pre-Gaelic settlement. But how it was concluded that they were short and black-haired I do not know. Seems like a silly thing to make a fuss over in any case. - -