My gggfather Martin Heheir was born in Limerick, but had moved to London by the time of the 1841 Census. This seems too early for the Potato Famine to have played a part in his emigration. (There was another family called Heheir in London by 1844). This indicates that the O' might be lost at an earlier date. The story might, of course, be legend, but no less interesting for it. Surely it can be verified? Incidentally, none of my relations (Sullivans, Hennessys, Cronins) have an initial O, so can someone tell me how people with O' names spell them out loud: do they say O apostrophe etc.?
Lastly, I imagine this board can be accessed anywhere in the world. Am I right?