WILLIAM CAVENDISH, 1st duke of Devonshire (I 640-1707 ), English statesman, eldest son of the earl of Devonshire last men tioned, was born on Jan. 25, 164o. In 1661 he entered parliament, and soon showed himself a determined and daring opponent of the general policy of the court. In 1678 he was one of the com mittee appointed to draw up articles of impeachment against the lord treasurer Danby. In 1679 he was re-elected for Derby, and made a privy councillor by Charles II. ; but he withdrew from the board with his friend Lord Russell, when he found that the Roman Catholic interest uniformly prevailed. He carried up to the House of Lords the articles of impeachment against Lord Chief-Justice Scroggs, and when the king declared his resolution not to sign the bill for excluding the duke of York, afterwards James II., he moved in the House of Commons that a bill might be brought in for the association of all his majesty's Protestant subjects. He appeared in defence of Lord Russell at his trial, and after his condemnation he offered to exchange clothes with him in the prison, remain in his place, and so allow him to effect his escape. In Nov. 1684 he succeeded to the earldom. He opposed arbitrary government under James II. with the same consistency and high spirit as during the previous reign. An imprudent quarrel at court was punished by a fine of f 30,00o which he could not pay, and he was in prison for some time. After his discharge the earl occupied himself with the erection of a new mansion at Chats worth designed by William Talman, decorations by Verrio, Thornhill and Grinling Gibbons. The revolution again brought him into prominence. He was one of the seven who signed the original paper inviting the prince of Orange from Holland, and was the first nobleman who appeared in arms to receive him at his land ing. He received the order of the Garter, and was made lord high steward of the new court. In 1690 he accompanied King William on his visit to Holland. He was created marquis of Hartington and duke of Devonshire in He had married in 1661 the daughter of James, duke of Or monde, and was succeeded by his eldest son William as 2nd duke, and by the latter's son William as 3rd duke (viceroy of Ireland, The latter's son William (172o-64) succeeded in as 4th duke; he married the daughter and heiress of Richard Boyle, earl of Burlington and Cork, who brought Lismore castle and the Irish estates into the family; from Nov. 1756 to May 1757 he was prime minister, mainly in order that Pitt, who would not then serve under the duke of Newcastle, should be in power. His son William (1748-1811), 5th duke, was the husband of the beautiful Georgiana Spencer, duchess of Devonshire (1757-1806), and of the intellectual Elizabeth Foster, duchess of Devonshire (1757-1824), both of whom Gainsborough painted. His son Wil liam, 6th duke (179o-1858), died unmarried. The title passed in 1858 to his cousin William (18o8-91), 2nd earl of Burlington, as 7th duke, who, in 1829 was second wrangler at Cambridge, first Smith's prizeman and eighth classic, and subsequently became chancellor of the university.