William Henry Cavendish Cavendish-Bentinck, 3rd Duke of Portland (14 April 1738 – 30 October 1809) was a British Whig and then a Tory politician during the late Georgian era.

Stormont was to superintend all expenditures on his equipage, while Langlois was to hire local masters and direct the studies of the teenaged Titchfield.

He faced strong demands for conciliatory measures following years of coercion and taxation brought about by the British government's engagement in the American Revolutionary War.

[13] Portland resolved to make concessions and, overcoming the resistance of Lord Shelburne, the Home Secretary to whom he reported, convinced Parliament to repeal the Declaratory Act and to modify Poynings' Law.

[14] Following Rockingham's death, Portland resigned from Lord Shelburne's ministry along with other supporters of Charles James Fox.

[15] In April 1783, Portland was selected as the titular head of a coalition government as Prime Minister, whose real leaders were Charles James Fox and Lord North.

Along with many other conservative Whigs such as Edmund Burke, Portland was deeply uncomfortable with the French Revolution; he broke with Fox over that issue and joined Pitt's government as Secretary of State for the Home Department in 1794.

Portland's second government saw the United Kingdom's complete isolation on the continent but also the beginning of its recovery with the start of the Peninsular War.

He died on 30 October 1809 at Burlington House, Piccadilly, after an operation for a kidney stone, and was buried at St Marylebone Parish Church, London.

[18] He had lived expensively: with an income of £17,000 a year (worth £577,000 in 2005),[19] he had debts at his death computed at £52,000 (£1.76 million in 2005),[19] which were paid off by his succeeding son by selling off some property, including Bulstrode Park.