Annesley, Richard (1693–1761), 5th Baron Altham, 7th Viscount Valentia, 7th Baron Mountnorris, and 6th earl of Anglesey , was probably born in Exeter, Devonshire, in November 1693 and was baptised there on 26 November, second son of Richard Annesley (d. 1701), dean of Exeter, and Dorothy Annesley (Davey). His father succeeded to the title of Baron Altham, which passed in 1701 to the elder son, Arthur Annesley, who died in 1727, supposedly without legitimate issue. Richard Annesley thereupon succeeded him, and took his seat in the Irish house of lords (28 November 1727). In 1737 he succeeded his cousin as Viscount Valentia and earl of Anglesey, but in 1740 his right to the titles and to the family estates in Dublin, Meath, Wexford, and England was challenged by James Annesley (qv) (d. 1760), who claimed to be a legitimate son of Arthur Annesley, 4th Baron Altham, and who began by taking proceedings in the Irish courts to eject his uncle from the Meath estate. The nephew stated that he had as a child been sold into slavery in America by the uncle; the latter seems also to have attempted during James Annesley's trial for murder in England (1742) to influence witnesses so as to get his nephew hanged. On 16 September 1743, at the Curragh races, Richard Annesley and his retainers first attempted to provoke a duel, and then attacked James Annesley and his party; the younger man, fleeing, was knocked unconscious by a fall from his horse, and prosecuted the earl for assault in a trial at Athy, Co. Kildare, 3 August 1744; the older man was merely fined. The ejectment trial, celebrated as the ‘Annesley peerage trial’, attempted to decide whether James Annesley was the legitimate heir. The trial, the longest known in the Dublin court of exchequer (11–25 November 1743), went in favour of the claimant, but a subsequent case in chancery in London seems to have gone against him, at least as regards the English titles and estates, and he was never able to muster enough resources to oust his uncle.
The family tendency to informality, even downright carelessness, in matrimonial and successional matters was very marked in Richard Annesley, who had at least one illegitimate son and one illegitimate daughter by different women. He married Ann Prust (Prest, Phrust) in Devon on 25 January 1715, but deserted her after a few years; she lived until 1741. In 1727 he secretly married Ann (Anne, Anna) Simpson (d. 1765), teenage daughter of a wealthy Dublin merchant, John Simpson, who was only reconciled to the marriage when Annesley agreed to another ceremony in public; after some years, probably in 1740, Annesley ejected his wife and their three daughters from his house, refused her any maintenance, and apparently tried to steal her legal papers. In 1741 she accused him in the ecclesiastical courts of cruelty and adultery; he retaliated by trying to prove her an adulteress. His main defence rested on the claim that the marriage with Ann Simpson was invalid because his first wife was still alive. When he refused to pay alimony as directed by the court, he was excommunicated. The earl had three daughters and a son in the course of a liaison with Juliana Donnovan, said to be daughter of a Camolin alehouse-keeper. They married publicly in 1752, but the legitimacy and thus the right of their son (b. 1744) to succeed to the family titles and estates was the subject of further celebrated legal proceedings in Ireland (1765) and England (1766). The Irish authorities accepted evidence of a secret marriage in 1741, which the English committee of privileges (1770–71) rejected as a forgery; the earl's English peerage thus became extinct. Richard Annesley, who had never attempted to live up to the family motto Virtute amoris, died, still excommunicate, at Camolin Park, Co. Wexford, on 4 or 14 February 1761. Lady Dorothea Du Bois (qv) was a daughter of the marriage to Ann Simpson.