Robert Knight, 1st Earl of Catherlough

Robert Knight, 1st Earl of Catherlough, KB, (1702–1772), was a British Member of Parliament for Great Grimsby (1734–41, 1762–68), Castle Rising, Norfolk (1747–54) and Milborne Port, Somerset (1770–72).

His estates were seized by the South Sea Company, which sold Luxborough to Sir Joseph Eyles (d.1740), Alderman & Sheriff of the City of London & MP for Devizes (1724–5) & Southwark (1727–30).

[5] Henrietta was thus half-sister of the highly influential Henry St John, 1st Viscount Bolingbroke, the son of her father's first marriage.

In the general election of 1761 Luxborough procured the return of his son Henry as MP for Great Grimsby, as 1st member.

On the sudden death of his son in August 1762, Luxborough decided to stand himself in the resultant by-election, and was returned unopposed, holding the seat until 1768.

[8] In 1770 he stood successfully as 2nd member in the by-election for Milborne Port, Somerset, which seat he held until his death on 30 March 1772, aged 69.

Horace Walpole's correspondence suggests she was caught by her husband in flagrante delicto with her doctor, whilst other sources add a further lover in the form of a young cleric named John Dalton (1709–1763).

Dalton had been employed as tutor to the children of Henrietta's close friend Frances Thynne (1699–1754), known until 1748 as Lady Hertford, wife of Algernon Seymour, 7th Duke of Somerset.

As Henrietta, Lady Luxborough, she was one of the first to establish a ferme ornée and is credited by the OED with at least the first recorded use, if not the invention of the word "shrubbery".

After his wife Henrietta's death on 26 March 1756, Luxborough began to live at Barrells and married secondly on 18 June 1756 Lady le Quesne.

She was the widow of Sir John le Quesne (d.1741), Alderman of London, née Mary Knight, from Hampshire, who provided a dowry of £20,000 to her first husband.

A Silver tea kettle was made for the 1738 marriage of Sir John Le Quesne to Mary Knight by the Huguenot silversmith Paul de Lamerie(d. 1751), now in the collection of the Courtauld Institute, London.

[14] Luxborough however became involved in an affair with Jane Davies, the daughter of a labourer in Henley-in-Arden, which resulted in several illegitimate children.

When his son married in 1791 he commissioned the Italian architect Joseph Bonomi the Elder to build an imposing extension, which thereafter became the main house.