O'Reilly
| O'Reilly Ó Raghallaigh |
|
|---|---|
 |
|
| Country | Kingdom of Connacht |
| Parent house | Uí Briúin Bréifne |
| Titles |
|
| Founder | Ragheallach mac Cathalan |
| Cadet branches | Brady Vesey |
O'Reilly (Irish: Ó Raghallaigh) is a group of families, ultimately all of Irish Gaelic origin, who were historically the kings of East Bréifne in what is today County Cavan. The clan were part of the Connachta's Uí Briúin Bréifne kindred and were closely related to the Ó Ruairc (O'Rourkes) of West Bréifne. O'Reilly is ranked tenth in the top twenty list of Irish surnames.
It is also the patronymic form of the Irish name Reilly (Irish Gaelic: Uí Raghaile). It is commonly found throughout Ireland, with the greatest concentration of the surname found in County Cavan followed by Longford, Meath, Westmeath, Fermanagh and Monaghan, and the Province of Leinster.
It is usually anglicised as , and O'Reilly. The original form of the name, Ó Raghallaigh, denotes "from/of Raghallach", the name Raghallach thought to be derived from the compounds ragh (meaning "race") and ceallach (meaning "sociable").
The Ó Raghallaigh family were part of the Connachta, with the Raghallach said to have died at the Battle of Clontarf in 1014. The family became the kings of East Breifne, modern-day County Cavan and County Longford.
The name is common and widespread throughout Ireland, ranked 8th most common in 1890 and 11th in 1996.
People with the surname O'Reilly include:
...
Wikipedia