Sir Donat O’Brien, 1st Baronet O'Brien of Lemeneagh and Dromoland

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Donough O'Brien

Also Known As: "Sir Donough O'Brien", "1st Bt.; Donat O'Brien"
Birthdate: (75)
Birthplace: County Clare, Munster, Ireland
Death: November 18, 1717 (75)
Place of Burial: near Newmarket-on-Fergus, County Clare, Munster, Ireland
Immediate Family:

Son of Conor MacDonogh O'Brien and Máire Rúa ní Mahon
Husband of Lucia O'Brien and Elizabeth O'Brien
Father of Lucius Dromoland O'Brien; Elizabeth O'Brien; Henry O'Brien, of Stonewall and Honora O'Brien
Brother of Honora O'Brien; Mary O'Brien and Tiege O'Brien
Half brother of Daniel Neylan; William Neylan; Michael Neylan and John Neylan

Occupation: 1st Baronet O'Brien, of Lemeneagh and Dromoland
Managed by: John Peter Cowley
Last Updated:

About Sir Donat O’Brien, 1st Baronet O'Brien of Lemeneagh and Dromoland

Sir Donough O'Brien, 1st Baronet (1642 – 17 November 1717) was an Irish politician and baronet.

Parents: son of Col. Conor O’Brien, of Leamaneagh, Co. Clare and his wife Mary “Maureen Rhue” McMahon.


  1. firstly Lucia Hamilton, daughter of Sir George Hamilton, 1st Baronet
  2. Secondly he married Elizabeth Deane, daughter of Major Joseph Deane

Child of Lucia Hamilton and Donough O'Brien:

  1. Lucius O'Brien. Lucius was the father of Sir Edward O'Brien, 2nd Baronet.[2]

Child of Elizabeth Deane and Donough O'Brien:

  1. Henry O'Brien


In 1692, O'Brien entered the Irish House of Commons, sitting for Clare until 1714.[1]

When Murrough O'Brien, 1st Earl of Inchiquin was captured Lady Inchiquin petitioned for her husband's release but Sir Donough O'Brien wrote that she had no mind to see any of his relations "for his being a papist".[3]


Sir Donat O’Brien was son of Col. Conor O’Brien, of Leamaneagh, Co. Clare, and the notorious Mary Mac Mahon his wife (“Maureen Rhue”), who played a marked part in the rising of 1641. Conor fell in a skirmish with General Ludlow, and was brought nearly dead to Leamaneagh, 1652. Mary, as soon as he was dead, drove to Limerick, and made terms with the Parliamentary Generals, thus saving the property for her son. She is said to have married Cornet Cooper, a parliamentary officer, on the evening of the day of her husband’s (Conor) death.

After the Restoration Donat took a prominent place in Co. Clare, and represented it in Parliament, 1695 to 1713. He was created a baronet in 1686. The gateway at Leamaneagh Castle bears the tablet of his father and mother, and his own coat-of-arms with the red hand.

He died November 18th, 1717, aged 76, which shows that he was born in 1611. His will (Dublin Registry of Deeds, Book xix, p. 360) desires that “My body be decently buried in my parish church of Kileenesula, in said county, in such a manner as to my son Henry O’Brien shall seem decent and agreeable.”



  1. Leigh Rayment - Irish House of Commons 1692-1800". Retrieved 28 August 2009.
  2. Burkes Royal Descents 1864.
  3. Bagwell, p. 326. Cites: Dromoland MS.
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Sir Donat O’Brien, 1st Baronet O'Brien of Lemeneagh and Dromoland's Timeline

County Clare, Munster, Ireland
Age 9
Leamaneh, County Clare, Munster, Ireland
Age 33
June 1679
Age 37
November 18, 1717
Age 75