# Henry O'Brien, 5th Earl of Thomond

Henry O'Brien, 5th Earl of Thomond PC (Ire) (1588–1639), styled Lord Ibrickane until 1624, was summoned to the House of Lords of the Irish Parliament of 1613–1615.

## Birth and origins

Henry was born the eldest son of Donogh O'Brien and Elizabeth FitzGerald. His father was the 4th Earl of Thomond. His father's family were the O'Briens, an important Gaelic Irish dynasty, that descended from Brian Boru, medieval high king of Ireland.
Henry's mother was the fourth daughter of Gerald FitzGerald, 11th Earl of Kildare and his wife Mabel Brown.
Family tree :
| | | | | | | Conor 3rd Earl c. 1535 – 1581 | Conor 3rd Earl c. 1535 – 1581 | Conor 3rd Earl c. 1535 – 1581 | Conor 3rd Earl c. 1535 – 1581 | Conor 3rd Earl c. 1535 – 1581 | Conor 3rd Earl c. 1535 – 1581 | | | Una O'Brien d. 1589 | Una O'Brien d. 1589 | Una O'Brien d. 1589 | Una O'Brien d. 1589 | Una O'Brien d. 1589 | Una O'Brien d. 1589 | | | Gerald FitzGerald 11th Earl Kildare 1525–1585 | Gerald FitzGerald 11th Earl Kildare 1525–1585 | Gerald FitzGerald 11th Earl Kildare 1525–1585 | Gerald FitzGerald 11th Earl Kildare 1525–1585 | Gerald FitzGerald 11th Earl Kildare 1525–1585 | Gerald FitzGerald 11th Earl Kildare 1525–1585 |
| | | Helen Roche d. 1583 | Helen Roche d. 1583 | Helen Roche d. 1583 | Helen Roche d. 1583 | Helen Roche d. 1583 | Helen Roche d. 1583 | | | Donogh 4th Earl d. 1624 | Donogh 4th Earl d. 1624 | Donogh 4th Earl d. 1624 | Donogh 4th Earl d. 1624 | Donogh 4th Earl d. 1624 | Donogh 4th Earl d. 1624 | | | Elizabeth FitzGerald d. 1617 | Elizabeth FitzGerald d. 1617 | Elizabeth FitzGerald d. 1617 | Elizabeth FitzGerald d. 1617 | Elizabeth FitzGerald d. 1617 | Elizabeth FitzGerald d. 1617 |
| Margaret O'Brien | Margaret O'Brien | Margaret O'Brien | Margaret O'Brien | Margaret O'Brien | Margaret O'Brien | | | Henry 5th Earl c. 1588 – 1639 | Henry 5th Earl c. 1588 – 1639 | Henry 5th Earl c. 1588 – 1639 | Henry 5th Earl c. 1588 – 1639 | Henry 5th Earl c. 1588 – 1639 | Henry 5th Earl c. 1588 – 1639 | | | Mary Brereton d. 1640 | Mary Brereton d. 1640 | Mary Brereton d. 1640 | Mary Brereton d. 1640 | Mary Brereton d. 1640 | Mary Brereton d. 1640 | | | Barnabas 6th Earl c. 1590 – 1657 | Barnabas 6th Earl c. 1590 – 1657 | Barnabas 6th Earl c. 1590 – 1657 | Barnabas 6th Earl c. 1590 – 1657 | Barnabas 6th Earl c. 1590 – 1657 | Barnabas 6th Earl c. 1590 – 1657 |
| | | | | | | Edward 2nd Marquess Worcester 1602–1667 | Edward 2nd Marquess Worcester 1602–1667 | Edward 2nd Marquess Worcester 1602–1667 | Edward 2nd Marquess Worcester 1602–1667 | Edward 2nd Marquess Worcester 1602–1667 | Edward 2nd Marquess Worcester 1602–1667 | | | Margaret O'Brien d. 1681 | Margaret O'Brien d. 1681 | Margaret O'Brien d. 1681 | Margaret O'Brien d. 1681 | Margaret O'Brien d. 1681 | Margaret O'Brien d. 1681 | | | | | Henry 7th Earl 1620–1691 | Henry 7th Earl 1620–1691 | Henry 7th Earl 1620–1691 | Henry 7th Earl 1620–1691 | Henry 7th Earl 1620–1691 | Henry 7th Earl 1620–1691 |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Henry Horatio d. 1690 d.v.p.* | Henry Horatio d. 1690 d.v.p.* | Henry Horatio d. 1690 d.v.p.* | Henry Horatio d. 1690 d.v.p.* | Henry Horatio d. 1690 d.v.p.* | Henry Horatio d. 1690 d.v.p.* |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Henry 8th Earl 1688–1741 | Henry 8th Earl 1688–1741 | Henry 8th Earl 1688–1741 | Henry 8th Earl 1688–1741 | Henry 8th Earl 1688–1741 | Henry 8th Earl 1688–1741 |
| XXX | XXX | XXX | XXX | XXX | XXX | Subject of the article | Subject of the article | Subject of the article | Subject of the article | Subject of the article | Subject of the article | XXX | XXX | XXX | XXX | XXX | XXX | Earls of Thomond | Earls of Thomond | Earls of Thomond | Earls of Thomond | Earls of Thomond | Earls of Thomond | XXX | XXX | XXX | XXX | XXX | XXX | Marquess of Worcester | Marquess of Worcester | Marquess of Worcester | Marquess of Worcester | Marquess of Worcester | Marquess of Worcester |

## Marriage and children

On 13 July 1608 O'Brien married Mary Brereton, a rich heiress, the only daughter of William Brereton, 1st Baron Brereton and Margaret Savage.
Henry and Mary had five daughters:
* Lady Mary (died 1686) married, on 24 June 1627, Charles Cokayne, 1st Viscount Cullen
* Lady Margaret, who married first Edward Somerset, 2nd Marquess of Worcester and secondly Donough Kearney
* Lady Elisabeth (1616–1659) married, on 21 August 1636, Dutton Gerard, 3rd Baron Gerard (1613–1640), grandson of Thomas Gerard, 1st Baron Gerard
* Lady Anne (died 1645) married, in 1641, Henry O'Brien, 7th Earl of Thomond
* Lady Honora married first Sir Francis Inglefield, knight of Wotton-Bassett, and secondly Sir Robert Howard, son of the Earl of Berkshire

## House of Lords

O'Brien was summoned on 3 March 1613 as Lord Ibrickane to the Irish House of Lords of the Irish Parliament of 1613–1615, the only parliament of King James I in Ireland.

## 5th Earl

Ibrickane succeeded his father on 5 September 1624 as the 5th Earl of Thomond.

## Death

Thomond died in 1639 and was buried in St Mary's Cathedral, Limerick. He had no son and was succeeded in his titles by his brother Barnabas O'Brien, 6th Earl of Thomond.