Select O'Reilly Surname Genealogy

O'Reilly is derived from the Gaelic O'Raghailligh, meaning descendant of Raghaillach (from ragh, a "race," and ceallach meaning "gregarious").  The story goes that Raghaillach was killed at the Battle of Contarf in 1014 while fighting alongside Brian Boru.  His descendants, the O'Reilly sept, followed Celtic traditions with their chief being inaugurated at an ancient stone circle on Seantomon hill outside of Cavan town.

Today it is O'Reilly more in Ireland, Reilly more outside.  And Reilly has often become Riley.

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IrelandThe O'Reillys were the most powerful sept of the old Gaelic kingdom of Breffny which comprised present-day Cavan and surrounding counties.  For a time they lay under the shadow of the stronger O'Rourke clan.  They also fell foul of Norman incursions into their territory. 

However, a new chief, Giaolla Iosa O'Reilly, re-established O'Reilly control in the early 1300's and helped develop Cavan as a thriving market town.  The O'Reillys were able to maintain their position for over two hundred years.  Their stongholds were Clogh Oughter castle and Tullymongan hill outside of Cavan town.

The O'Reilly were widely involved in trade at this time.  They created their own coinage by "clipping" English coins and at one time reilly was a term for Irish money.  It has also been suggested that they lived well, as the phrase "the life of Reilly" suggests. 

The English were eying Breffny in Tudor times.  They captured Cavan town in 1600.  Edmund O'Reilly of Kilnacrott was killed at that time, the last of the O'Reilly chiefs of Breffny, and lost his estates.  In the 1640's, during the Irish rebellion, the O'Reillys - led by Edmund's son Myles the Slasher - retook Clogh Oughter castle and were temporarily in power again.  But Clogh Oughter fell to Cromwell in 1653 and the English process of dispossession and confiscation of lands continued.  Hugh Reilly of Cavan supported the luckless Stuarts in 1690 and followed James II into exile.

The O'Reilllys suffered for their Catholic faith during the penal times.  Some "wild geese" became mercenaries abroad.  Many O'Reillys emigrated later.  In Ireland the largest numbers are in Dublin.  O'Reillys are still numerous in what was Breffny - Cavan and neighboring Longford.  The name is also quite common in Fermanagh and Monaghan.  Some 60% are called O'Reilly and 40% Reilly.

Spain and Austria.   Alejandro O'Reilly
left his home in Baltrasna, Meath during the penal times to fight for the Spanish army in the Irish Brigade.  A Field Marshal and Count, he was sent to Cuba in 1769 to quell disturbances there.  One of Havana's streets is called Calle Orely and his descendants are still to be found there.

Colonel Edmund O'Reilly commanded O'Reilly officers in the Spanish and Austrian armies during the 1700's.  Count Andrew O'Reilly of Westmeath was a Field Marshal in the Austrian army who, as Governor of Vienna, had the humiliation of surrendering the city to Napoleon in 1809. 

.  O'Reillys and Reillys came to England in the 19th century and primarily to Lancashire.  James Reilly was in Manchester sometime by the 1820's.  He and his sons were cabinet-makers and skilled ones too.  Their trade expanded until by the late 1800's they had even begun to export their furniture.  

But many Reillys arrived and lived in poverty and overcrowding.  Eight members of a Reilly family together with eleven lodgers were recorded as living in a tiny cellar dwelling on John Street in Manchester during the 1850's.   

America.  O'Reilly emigration to America also stepped in in the 19th century.  Many left during the famine times.  John Riley came in the 1840's, started off fighting for the US Army in the Mexican War, and then left them to fight on the Mexican side.  Andrew O'Reilly came to America via Canada.  As also did James O'Reilly:

"Articles about James O'Reilly who emigrated between 1849 and 1852 suggest that it took him eight weeks to come by a boat that was shipwrecked and landed in Newfoundland.  He came to Troy, New York where he worked as a farm laborer for three years.  Perhaps he, like many other Irish emigrants, sent money home to his family, enabling his brother Michael to follow him to America and perhaps helping to keep those who stayed at home alive."

John Boyle O'Reilly was a man who made the journey to America through unusual routes.  He had been transported to Australia in 1867 because of his involvement in militant Fenian groups.  But he escaped, made his way to Boston, and became a supporter of Irish causes there and the well-respected editor of the Pilot newspaper.

Alexander O'Reilly, a descendant of the O'Reillys in Cuba, grew up in Philadelphia and became a well-known doctor.  He was personal physician to President Cleveland and surgeon general to the US Army in the early 1900's.

Canada.  Peter O'Reilly, the son of an Irish father and English mother, left Ireland in 1859 for the opportunities that might be presented in the new western colony of British Columbia.  He prospered there in forty years of Government service.  In 1868 he bought a large home in Victoria which was lived in by his descendants until 1975.  It is now known as Point Ellice House and is preserved as a museum.

Australia.  O'Reillys and Reillys who came to Australia included:
  • Joseph Reilly, who having retired from the British army came to Western Australia from Meath in 1853 with his wife Mary and settled in Perth.
  • Peter O'Reilly who arrived in New South Wales from Ulster in 1865.  His grandson Bill, nicknamed "Tiger," was the great spin bowler of the Australian cricket team in the 1930's. 
  • and Thomas O'Reilly and his family who left their native Roscommon for Melbourne on the Lady Jocelyn in 1875.  They settled in Numurkah. 
The Green Mountains on Australia's Gold Coast was first settled in 1911 by an O'Reilly family.  They took up a number of small dairy farms before consolidating their holdings around what is now an internationally famous guesthouse in the rainforest.

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If you would like to read more, click on the miscellany page for further stories and accounts:

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Giaolla Iosa O'Reilly
restored the O'Reilly position in Cavan in the early 1300's and founded the Franciscan Abbey.
Myles O'Reilly, known as Myles the Slasher, became a folk hero in Ireland for his stand against the English during the Irish rebellion of the 1640's.  He died in battle in 1644.
Tony O'Reilly was an international rugby player for Ireland who became the CEO of Heinz Corporation.
Paddy Reilly is one of Ireland's best-known balladeers.
Bill O'Reilly is a prominent face on American TV today through his O'Reilly Factor show on Fox TV.

Select O'Reillys and Reillys Today
  • 29,000 in the UK (most numerous in Lancashire)
  • 34,000 in America (most numerous in New York) 
  • 52,000 elsewhere (most numerous in Ireland)

PS.  You might want to check out the surnames page on this website.  It covers surname genealogy in this and companion websites for more than 800 surnames.

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