William Cavendish, 4th Duke of Devonshire

For other persons named William Cavendish, see William Cavendish (disambiguation).

His Grace The Duke of Devonshire

Prime Minister of Great Britain
In office 16 November 1756 – 25 June 1757
Preceded by	The Duke of Newcastle-upon-Tyne
Succeeded by	The Duke of Newcastle-upon-Tyne

Born	1720
Died	2 October 1764 Spa, Belgium
Political party	n/a (Whig)

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

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 of Hardwick 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. 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. In 1762, he was sworn of the Privy Council of Ireland.

He married Lady Charlotte Elizabeth Boyle, Baroness Clifford (1731–1754), the daughter and heiress of the 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.

[edit] 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)

Parliament of Great Britain
Preceded by Sir Nathaniel Curzon, Bt Lord Charles Cavendish	Member of Parliament for Derbyshire with Sir Nathaniel Curzon, Bt 1741–1751	Succeeded by Sir Nathaniel Curzon, Bt Lord Frederick Cavendish
Political offices
Preceded by The Duke of Richmond	Master of the Horse 1750–1755	Succeeded by The Duke of Dorset
Preceded by The Duke of Dorset	Lord Lieutenant of Ireland 1755–1757	Succeeded by The Duke of Bedford
Preceded by The Duke of Newcastle-upon-Tyne	Prime Minister 1756–1757	Succeeded by The Duke of Newcastle-upon-Tyne
Preceded by The Duke of Newcastle-upon-Tyne	Leader of the House of Lords 1756–1757	Succeeded by The Duke of Newcastle-upon-Tyne
Preceded by The Duke of Grafton	Lord Chamberlain 1757–1762	Succeeded by The Duke of Marlborough
Honorary Titles
Preceded by The Duke of Devonshire	Lord Lieutenant of Derbyshire 1756–1764	Succeeded by Marquess of Granby
Peerage of England
Preceded by William Cavendish	Duke of Devonshire 1755–1764	Succeeded by William Cavendish
Preceded by William Cavendish	Baron Cavendish of Hardwick 1751–1764	Succeeded by William Cavendish