Arthur Annesley, 1st Earl of Mountnorris
He was the son of Richard Annesley, 6th Earl of Anglesey, and the Countess Juliana Donovan, who belonged to the junior sept of the O'Donovans of Clan Loughlin, the Donovans of Ballymore in County Wexford. She was initially rumoured to be of lower birth, the ancient pedigrees of some Irish families not being widely known in the English-speaking world at that time, and hers deriving from a remote region of Ireland, the Barony of Carbery. The Countess Juliana was the great-great-great-granddaughter of Donel Oge na Cartan O'Donovan, the 1st Lord of Clan Loughlin to hold his territories from the Crown, from 1616 (see surrender and regrant).
On 22 April 1771, the House of Lords decided that his claim to his father's English titles was not valid, and that therefore these titles had become extinct on his father's death in 1761. He was created 1st Earl of Mountnorris [Ireland] on 3 December 1793.
He married, Lucy Lyttelton, daughter of George Lyttelton, 1st Baron Lyttelton of Frankley, and Lucy Fortescue, on 10 May 1767. They had, among other children:
- George Annesley, 2nd Earl of Mountnorris (2 Nov 1769 – 23 July 1844)
He next married Sarah Cavendish, daughter of Sir Henry Cavendish, 2nd Baronet, and Sarah Bradshaw, 1st Baroness Waterpark, on 20 December 1783. They had, among other children:
- Catherine Annesley  (? – 25 June 1865) – married John Thomas Somerset, a younger son of Henry Somerset, 5th Duke of Beaufort, and had issue.
- A genealogical history of the dormant, abeyant, forfeited, and extinct peerages of the British empire, Sir Bernard Burke, Harrison, 1866
- Who's who, Volume 59, Henry Robert Addison, Charles Henry Oakes, William John Lawson, Douglas Brooke Wheelton Sladen, A. & C. Black, 1907
- Burke, Bernard and Ashworth Peter Burke, A Genealogical and Heraldic History of the Landed Gentry of Ireland. London: Harrison & Sons. 9th edition, 1899. p. 119
|Peerage of Ireland|
|New title|| Earl of Mountnorris
1793 – 1816
| Viscount Valentia|
1761 – 1816