William Cavendish, 4th Duke of Devonshire, KG, PC (8 May 1720 – 2 October 1764), styled Lord Cavendish before 1729 and Marquess of Hartington between 1729 and 1755, was a British Whig statesman who was briefly titular Prime Minister of Great Britain.

Early career

He was elected MP for Derbyshire in 1741 and 1747, but left the House of Commons for the Lords in 1751 by a writ of acceleration as Baron Cavendish and was sworn of the Privy Council. He was Lord Lieutenant of Ireland from 2 April 1755 until 3 January 1757, when his successor, the 4th Duke of Bedford, entered the office.

Prime Minister

After inheriting his father's peerage titles (chiefly the Dukedom of Devonshire), Devonshire was given the Garter and appointed First Lord of the Treasury (most historians consider him Prime Minister during this service) in November 1756, and he served as First Lord until May 1757 in an administration effectively run by William Pitt the Elder. The administration was eventually brought down for a variety of reasons including the opposition of George II and the alleged mishandling of the trial and execution of Admiral John Byng. It was replaced by the Second Newcastle Ministry headed by the Duke of Newcastle and including Pitt, Henry Fox and the Duke of Bedford. This government steered Britain through most of the Seven Years War leading the country to ultimate victory.

Later career

In 1762, he was sworn of the Privy Council of Ireland. He had long had a weak constitution and he gradually grew more ill during these years. He ultimately died in the Austrian Netherlands where he had gone to take the waters at Spa. His death was a large political loss to his allies, the Whig magnates such as Duke of Newcastle.

Family

He married Lady Charlotte Elizabeth Boyle, 6th Baroness Clifford (1731–1754), the daughter and heiress of Richard Boyle, 3rd Earl of Burlington of the 1st creation, a famous architect and art collector. Through her, the Devonshires inherited Chiswick House and Burlington House in London; Bolton Abbey and Londesborough Hall in Yorkshire; and Lismore Castle in County Waterford, Ireland. The Duke employed Capability Brown to landscape the garden and park at Chatsworth House, his main residence. He hired James Paine to design the new stable block.

The Duke had four children:

• William Cavendish, 5th Duke of Devonshire (1748–1811)
• Lady Dorothy Cavendish (1750–1794). Married William Cavendish-Bentinck, 3rd Duke of Portland, who also became Prime Minister.
• Lord Richard Cavendish (1752–1781)
• George Augustus Henry Cavendish, created 1st Earl of Burlington of the 2nd creation (1754–1834). Lord Burlington's grandson, the 2nd Earl of Burlington, would later inherit the Devonshire dukedom as 7th Duke of Devonshire.

Titles from birth to death

• Lord Cavendish of Hardwick (1720-1729)
• Marquess of Hartington (1729-1741)
• Marquess of Hartington, MP (1741-1751)
• The Rt. Hon. Marquess of Hartington (1751-1755)
• His Grace The Duke of Devonshire, PC (1755-1756)
• His Grace The Duke of Devonshire, KG, PC (1756-1764)

References

External links

• More about William Cavendish, Duke of Devonshire on the Downing Street website.