The Oreily surname originally appeared in Gaelic as O Raghailligh, which means descendant of Raghallach.
The surname Oreily was first found in County Cavan. They were known as the Princes of East Breffny, descended from Raghallaigh, Prince of Breffny in 981. They maintained their territory during the Anglo/ Norman invasion of Strongbow, Earl of Pembroke, in 1172, but Sir John O'Reilly, Prince of Breffny surrendered the principality to Queen Elizabeth I thereby ensuring that his territories remained intact.
This web page shows only a small excerpt of our Oreily research. Another 95 words (7 lines of text) covering the years 1598, 1669, 1630, 1695, 1689, 1640, 1703, 1689, 1646, 1691 and 1667 are included under the topic Early Oreily History in all our PDF Extended History products and printed products wherever possible.
Pronunciation, rather than spelling, guided scribes and church officials when recording names during the Middle Ages. This practice often resulted in one person's name being recorded under several different spellings. Numerous spelling variations of the surname Oreily are preserved in these old documents. The various spellings of the name that were found include O'Reilly, O'Reilley, O'Reily, O'Rielly, O'Riely, O'Riley, O'Rilley, Reel and many more.
Notable amongst the family name at this time was Count John O'Reilly; Edmund O'Reilly (1598-1669), Roman Catholic Archbishop of Armagh; Hugh Reily (Reilly or O’Reilly) (c.1630-1695) Irish Member of Parliament for Cavan Borough in the Patriot Parliament of 1689; Philip Og O’Reilly (Gaelic was Phillip Óg O’Raghallaigh)(c.1640-1703), Irish...
Another 48 words (3 lines of text) are included under the topic Early Oreily Notables in all our PDF Extended History products and printed products wherever possible.