Colonel Richard St George Mansergh of Headford Castle, Co. Galway was the nephew of Richard St George, founder of the Hatley Manor, Co. Leitrim branch of the family. His grandfather was Richard St George of Carrickdrumarusk aka Carrick on Shannon, Co Leitrim. 

The St Georges of Headford Castle and of Tyrone both trace their ancestry back through the female line to the St Georges of Hatley St George, Cambridgeshire. Richard St George, a member of a Cambridgeshire family, came to Ireland in the 17th century and was appointed Governor of the town of Athlone. His ownership of lands in counties Galway, Roscommon, Limerick and Queen's county (county Laois) was confirmed by a patent dated 26 Oct 1666.

His grandson, Richard St George of Carrick on Shannon, Co. Leitrim, had two natural children, Richard St George, founder of the Hatley Manor, Co. Leitrim branch of the family and Mary St George, who married James Mansergh.

In 1771, Colonel Richard St George Mansergh inherited his uncle's estate and added 'St. George' to the end of his surname, hence Richard St. George Mansergh-St. George Esq. He employed Charles Frizell to survey his estate in the early 1770s. [See University of London, Senate House Library: Volume of maps and rent rolls of the estates of Sir Richard St George in Counties Cork, Tipperary & Kilkenny by Charles Frizell, 1775].

He began his military career in late 1775 and served in the American War of Independence. He survived a shot in the head at the Battle of Germantown 1777.

In Sept 1778, the estate of Richard St. George Esq. in Co. Roscommon was advertised TO LET. The Rev. Mr Bennett was agent to the estate in Carrick. [Hibernian Journal  30 September 1778]. 



In May 1785, having suffered a head injury in the American War, Col. Mansergh St George returned to Ireland and was an active, local magistrate.  Appalled by the poverty that he found on his estates in County Cork and County Galway, he wrote an Account of the State of Affairs in and About Headford, County Galway, lamenting the condition of the Irish peasantry.  [Held at Trinity College Dublin]. By the late 1780s, he was the only active magistrate to oversee the vast mountainous tract of land between Cork and Tipperary.


On 12 February 1798, at the outbreak of the Irish Rebellion of 1798, the Colonel was visiting the house of one of his squires, Jasper Uniacke, Esq. when it was attacked by 30 Rebels from North Cork and South Tipperary. According to the Hibernian Chronicle, they "demanded that St. George Mansergh, who was then in the house, should be sent out to them; this being refused, they rushed in to seize him, on which he shot one of them dead, which so exasperated the rest, that with pitchforks, and other weapons," was "barbarously murdered" along with his servant with a rusty scythe. The newspaper article continues to describe the murder: "And to add to their inhumanity, they wounded Mrs. Uniacke, while in the act of saving her husband, so that she lies dangerously ill." She survived and identified two of the assailants, John Haye and Timothy Hickey, at their trial later in 1798: both men were found guilty and executed at Araglin.


His Landed Estates' Court Rentals can be viewed on Microfilm at the National Archives of Ireland.


Additional Information
Date of Birth 1st Jan 1757 VIEW SOURCE
Date of Death 12th Feb 1798 VIEW SOURCE
Associated Building (s) Holywell House CARRICK ON SHANNON  
Mother (First Name/s and Maiden) Mary St. George, daughter of Lieutenant General Richard St George of Headford, Co. Galway (Commander of the Forces in Ireland)| born 1710 in Headford, County Galway (uncertain) | married 1749 (2nd wife of James Mansergh) VIEW SOURCE
Father (First Name/s and Surname) Captain James Mansergh Esq. | born about 1725 in Macrony Castle, Kilworth, County Cork. VIEW SOURCE
Names of Siblings He was Mansergh's only son VIEW SOURCE
Spouse (First Name/s and Maiden/Surname) m. 1788 Anne Stepney (1766-1791) of Durrow, County Laois (then Queen's County)
Names of Children Richard James Mansergh-St George Esq. (1789-1857) of Headford (High Sheriff of County Galway in 1818) | Stepney St George Mansergh-St George (1791-1847)
Occupation Landed Estate Owner, British Army Colonel and magistrate of County Cork.
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  • Anne Stepney was from Durrow Abbey in Co. Offaly (King's County)


    Monday 27th May 2019 10:51AM

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