William O'Brien, 4th Earl of Inchiquin [SEP] date of death
William O'Brien, 4th Earl of Inchiquin
William McWilliam O'Brien, 4th Earl of Inchiquin, KB, PC(I) (1700 – 18 July 1777) was an Irish peer and Whig politician who sat in the House of Commons between 1722 and 1754.
Background.
O'Brien was the eldest son of William O'Brien, 3rd Earl of Inchiquin, and his wife, Mary (née Villiers), sister of the 1st Earl of Jersey, and inherited his father's titles in 1719. He founded the predecessor of the present day
of Inchiquin (1654).
- Murrough O'Brien, 1st Earl of Inchiquin, 6th Baron Inchiquin (1618–1674)
- William O'Brien, 2nd Earl of Inchiquin, 7th Baron Inchiquin (1640–1692)
- William O'Brien, 3rd Earl of Inchiquin, 8th Baron Inchiquin (1662–1719)
- William O'Brien, 4th Earl of Inchiquin, 9th Baron Inchiquin (1700–1777)
- Murrough O'Brien, 5th Earl of Inchiquin, 10th Baron Inchiquin (1726–1808) (created Marquess of Thomond in 1800)
Marquesses of Thomond (1800