Quote Originally Posted by O'Callaghan View Post
Only two or three of them correspond to Scottish clans, and even with those you have to remember that the highlanders came to Scotland from Ireland, not the other way around, so even where the tartan was originally adopted in Scotland the clan itself invariably existed in Ireland first and then spread to Scotland, not vicea versa. That is a common mistake when people think they recognise 'Scottish' names in Ireland, i.e. if they are highland clan names then they are in fact Irish names that occur in Scotland.

OTOH, lowland Scots and a even a few highlanders did settle in the North of Ireland many centuries later, so it can be hard to unscramble, but many people get it wrong because they have heard of that migration and not the earlier one in the other direction.

This brings up an interesting questions. If you find out from genealogical research that you are descended from a Scots clan name solely via Ireland and have no Scots blood can you still wear the tartan? I'd say yes, if it's the same clan, but not everyone would agree.
Irish names occurring in Scotland actually come from two sources:

1) As the bulk of Gaelic surnames are patronymics, it is highly probable that two unrelated surnames would appear in both countries at the same time. Though based on the same male personal name they are, in fact, not connected. The Scotii stopped migrating to Scotland long before the 'surname period' in Ireland occurred. (Reputed to be in the reign of Brian Boru.)

2) Irish emigration to Scotland occurring during the middle of the 19th Century. By the 1850s, a large bulk of the working-class in Glasgow were Irish. Their descendants are still numerous today.

Scottish surnames occurring In Ireland:

Lowland Scots (and some English) did migrate en masse to Ulster commencing in the 17th Century. Indeed, many names of non-Irish origin can be found all over Ireland. However, a source of Scottish (Gaelic) surnames in the North is often overlooked: Gallowglass. Many Highlanders fought for the Uí Néill and the Uí Dónaill. These soldiers-of-fortune were often granted land as payment. These individuals/families were easily assimilated into the native Irish population.