Colonel John O'Mahony (1816-1877)

John O'Mahony was born in Kilbeheny, Co. Limerick, Ireland in 1816 into an Irish speaking, aristocratic family.  The O'Mahony family was one of the few Gaelic families in Munster who held on to their ancestral lands after the plantation of Ireland in the 16th and 17th centuries.  Members of the family had been outspoken advocates for the rights of the native Irish during the Penal Laws period of the late 17th and early 18th centuries.  O’Mahony’s father and uncles participated in the United Irishman uprising of 1798 and narrowly avoided execution as a result of the death of their chief enemy, Lord Kingston, a local landowner. 

As a child O’Mahony lived and was reared on his family estate. He would later inherit the estate upon the death of his brother, and subsequently would relinquish it to his sister with his involvement with the young Ireland movement.

A fluent Irish speaker he received his early education at Hamlin's school in Middletown.  Despite the Roman Catholic Church’s ban on adherents’ attending Trinity College, a protestant University in Dublin, he, nevertheless, enrolled to pursue linguistic studies.  Sanskrit, Hebrew and Irish were the languages he specialized in.  After a number of years he withdrew from Trinity without obtaining a degree. 

Infused with a strong sense of national sentiment, no doubt inherited from his revolutionary-minded family, he became involved with Daniel O'Connell's Repeal Association. He attended many of O'Connell rallies in Cork and Tipperary.   O'Connell was a friend of his father. When the Young Ireland party seceded from O'Connell's Repeal Association at Conciliation Hall in Dublin in 1846, O'Mahony aligned himself the Young Irelanders. It was the Young Irelander’s belief that the use of force was the only alternative to the politically ineffective Repeal Association.  This belief was put into action with the uprising of 1848.

Unfortunately,  the rising was betrayed and subsequently failed.  This dealt a severe blow to the Young Ireland leadership. John Mitchel one of the prominent leaders of the Young Irelanders was quickly arrested. With news of Mitchel’s arrest, William Smith O'Brien and other Young Ireland leaders took to the hills to avoid capture and launched a series of attacks that eventually petered out in 1849.  O'Mahony and his band of volunteers were one of the last to cease activities.  Many of the leaders including William Smith O'Brien, Thomas Francis Meagher, James Stephens and Terence Bellew MacManus were eventually captured.  After sham trials  these men were  either a sentence of  death,  tortured in English prisons or exiled to the infamous prison colony in Van Dieman's Land.  O'Mahony, who eluded capture made his way to Paris where he met up with other Young Irelanders who also managed to escape to refuge in Paris. 

In 1853, John Mitchel escaped from Van Dieman's Land and made his way to the New York. Upon learning of Mitchel’s escape O'Mahony left Paris to join him there. Shortly after his arrival in New York Mitchel was chosen to lead 'The Emmet Monument Association".  This was the U.S based Irish national movement and predecessor to the Fenian movement. The association was ineffective in influencing events in Ireland. After Mitchel moved to Tennessee the association split into two factions. The faction that retained the old name was led by O'Mahony and Michael Doheny; the other faction named 'Emigrant Aid Association' was led by Robert Taylor the son of ex-President Tyler.

During this time period O'Mahony translated Keating's Foras Feasa ar Éirinn as The History of Ireland. The inclusion of notes from John O'Donovan's edition of the Annals of the Four Masters  prevented its sale in Ireland.  One of his own commentaries compared the modern struggle against English rule in Ireland with the ethos of the Fionn cycle, giving currency to the term most widely used for the Fenians.

In 1855, Michael Doheny organized a meeting in his New York law offices of men committed to the freedom of Ireland.  O’Mahony, James Roche, Thomas J. Kelly, Oliver Byrne, Patrick O’Rourke, and Captain Michael Corcoran were all in attendance. Out of this meeting emerged the Fenian Brotherhood, so named by O’Mahony. Its principle objects ware to supply money and arms to the Irish branch of the Fenians founded by James Stephens in Dublin on St. Patrick's Day of that same year.

At the onset of the  U.S. Civil War, O'Mahony held the rank of Colonel in the 99th New York Militia whose numbers were recruited from the ranks of the Fenian Brotherhood. The Civil War gave the Fenians a great opportunity to obtain military training.  However, by war's end the organization was in disarray and beginning to disintegrate into irreconcilable factions.  O'Mahony attempted to keep the organization intact but by the mid 1870's it had ceased to exist.

Due to the disarray within the organization, it was unable to support the planned uprising of 1867 in Ireland. Instead of sending trained soldiers, they opted instead to attack the British in Canada with the aim of holding Canada hostage for Ireland's freedom. O'Mahony helped organize what was to become known as the Fenian Raids into Canada.

O'Mahony spent his final years in ill health and poverty.  He passed away on February 7, 1877 in New York City. He remains were returned to Ireland for burial in the Fenian plot in Glasnevin Cemetery in Dublin.

Contributed by;  Tomás Ó Coısdealha

cemetery AND grave location

Name:        Glasnevin Cemetery                                      PHONE NO.      011 353 1 830-1133

ADDRESS:    Finglas Road, Glasnevin, Dublin 11, Ireland

GRAVE LOCATION:     Fenian Plot


click on headstone to view inscription

Back to Biographies                                                                                                                                                                    Posted 03/09/08