CAVENDISH, William, Mq. of Hartington (?1698-1755), of Chatsworth, Derbys.

Lord Hartington was returned on the government interest for Lostwithiel in 1721 and again in 1722, when he chose to sit for Grampound. On 15 Jan. 1723 he moved that the committee appointed by the Commons to examine one of the Atterbury plot conspirators should consist of privy councillors. Brought in for Huntingdonshire by the Duke of Manchester in 1727, he seconded, 7 May 1728, an address for a vote of credit.Knatchbull Diary, App. 128. A year later he succeeded to the dukedom, carrying virtually a prescriptive right to a seat in any Whig cabinet of this period. On seeing him kiss hands for the privy seal in 1731 the 1st Lord Egmont was reminded of Caligula’s making his horse consul; but he was set up as ‘the standard of Whiggism’ by Walpole,HMC Egmont Diary, i. 192; Walpole, Mems. Geo. II, i. 196. who on resigning wrote to him:

one of the greatest prides and pleasures of my life is that I have the honour to call you friend which is a title that I shall never forfeit, nor abandon.2 Feb. 1742, Cholmondeley (Houghton) mss.

He resigned in 1749 to retire with his Duchess to Chatsworth

after having parted with her and turned [i.e. sent her off] her head by breaking a promise he had given her of not marrying her son to Lord Burlington’s daughter.Walpole to Mann, 4 June 1749; Corresp. H. Walpole (Yale ed.), xx. 66 n. 24.

He died 5 Dec. 1755.