Irish names, what's the difference between 0'Somename and McSomename and just Somename ?

O'Connor / McGuinty / Rankin for some examples

Irish names, what's the difference between 0'Somename and McSomename and just Somename ?
The "O'-" prefix originates from the Irish "U铆" (pronounced "ee"), and means essentially "of", for instance the royal clan U铆 N茅ill (modern O'Neill) are descendants of Niall of the Nine Hostages.





In the Irish language, "mac" simply means "son", so McSweeney, for instance (Mac Suibne in Irish) means "son of Sweeney" in much the same way.





Other Irish names originate for many other reasons, just like in any ethnicity. For instance, one might be a soldier, or a carpenter, or a king; the descendants of that person might be named as "son of the King" or "son of the warrior". Or it might be descriptive of a function--the fairly common name of Gilchrist, for instance, in its original form "Giolla Cr铆ost" means "servant of Christ". Those who bear the name of Moore probably had an ancestor who was tall, large or otherwise "great", because the Irish word "m贸r" means just that. If you study the Irish language, you may find that Irish names begin to make much more sense once you translate them back into their original forms.
Reply:The successive invasions of Ireland from Strongbow to Cromwell, culminating in the final destruction of the Gaelic order and the long drawn out subjection of the Irish people under the eighteenth century penal code, together with the plantations of foreign settlers and the more peaceful infiltration of Englishmen in the commercial life of the country, have made Irish surnames more mixed than those of a nation with a less disturbed history. The situation can no doubt be paralleled in several mid-European states, but there is nothing comparable to it in any of our nearer neighbors such as England, France, Germany, Holland or Spain, where foreign names are exceptional and native ones are seldom hidden under alien guise. This latter is a phenomenon which is extremely common in Ireland.





It has often been stated that surnames were introduced into Ireland by King Brian Boru.


Ireland was one of the first countries to adopt a system of hereditary surnames


At any rate the Macs and O's were well established as such more than a century before the Cambro-Normans or, as they are more usually called, the Anglo-Normans, came.





It is hardly necessary to state that these prefixes denote descent, mac (son) indicating that the surname was formed from the personal names, or sometimes calling, of the father of the first man to bear that surname, while O names are derived from a grandfather or even earlier ancestor, o or ua being the Irish word for grandson, or more loosely male descendant.









Reply:I found this link to be very handy; Its all about Irish names in history.
Reply:O is decendent or ancestor of .


Mc, Mac etc is son of.


Ni is daughter of.
Reply:O' means descendant of or some will say grandson of.





Mc, Mac, Fitz means son of.