William Cavendish, 1st Duke of Devonshire

William Cavendish, 1st Duke of Devonshire KG PC (25 January 1640 – 18 August 1707) was an English soldier, politician and Whig politician who sat in the House of Commons from 1661 to 1684 when he inherited the peerage as Earl of Devonshire. He was created Duke of Devonshire in 1694.

Life
Cavendish was the son of William Cavendish, 3rd Earl of Devonshire and his wife Lady Elizabeth Cecil. In 1661, he was elected Member of Parliament for Derbyshire in the Cavalier Parliament. He was a Whig under Charles II of England and James II of England and was leader of the anti-court and anti-Catholic party in the House of Commons, where he served as Lord Cavendish. He was re-elected MP for Derbyshire in the two elections of 1679 and in 1681. In 1684 he succeeded to the peerage as Earl of Devonshire on the death of his father and then sat in the House of Lords. He was a strong supporter of the "Glorious Revolution" of 1688 which brought William III of Orange to the throne, signing as one of the Immortal Seven the invitation to William.

After the revolution, Cavendish was a leading Whig, serving as William's Lord Steward, and was created the Duke of Devonshire (1694) and also Marquess of Hartington in recognition for his services. He rebuilt Chatsworth House.

Cavendish was given an honorary MA by the University of Cambridge in 1705.

Family
Cavendish married Lady Mary Butler (1646–1710), daughter of James Butler, 1st Duke of Ormonde and his wife, Lady Elizabeth Preston, on 26 October 1662. They had four children:
 * Lady Elizabeth Cavendish (1670–1741), married Sir John Wentworth, 1st Baronet and had issue
 * William Cavendish, 2nd Duke of Devonshire (c. 1672 – 4 June 1729)
 * Lord Henry Cavendish (1673 – 10 May 1700)
 * Lord James Cavendish (d. 14 December 1751)