William Petty Fitzmaurice, 1st Marquess of Lansdowne (2 May 1737 – 7 May 1805), known as the Earl of Shelburne between 1761 and 1784, by which title he is generally known to history, was an Anglo-Irish Whig statesman who was the first home secretary in 1782 and then prime minister in 1782–83 during the final months of the American War of Independence.

Shelburne lamented that his career had been a failure, despite the many high offices he held over 17 years, and his undoubted abilities as a debater.

His grandfather, Lord Kerry, died when he was four, but Fitzmaurice grew up with other people's grim memories of the old man as a "tyrant", whose family and servants lived in permanent fear of him.

Fitzmaurice spent his childhood "in the remotest parts of the south of Ireland,"[a] and, according to his own account, when he entered Christ Church, Oxford, in 1755, he had "both everything to learn and everything to unlearn".

From a tutor whom he describes as "narrow-minded" he received advantageous guidance in his studies, but he attributes his improvement in manners and in knowledge of the world chiefly to the fact that, as was his "fate through life", he fell in "with clever but unpopular connexions".

[7] He was succeeded in Wycombe by one of his supporters Colonel Isaac Barré who had a distinguished war record after serving with James Wolfe in Canada.

[15] In 1795 he described this to Dugald Stewart: I owe to a journey I made with Mr Smith from Edinburgh to London, the difference between light and darkness through the best part of my life.

The novelty of his principles, added to my youth and prejudices, made me unable to comprehend them at the time, but he urged them with so much benevolence, as well as eloquence, that they took a certain hold, which, though it did not develop itself so as to arrive at full conviction for some few years after, I can fairly say, has constituted, ever since, the happiness of my life, as well as any little consideration I may have enjoyed in it.

Fox held the lucrative but unimportant post of Paymaster of the Forces, but commanded large support in the House of Commons and could boost Bute's power base.

Eventually, a deal was agreed but it was heavily criticised for the perceived leniency of its terms as it handed back a number of captured territories to France and Spain.

Shortly afterwards, Bute chose to resign as Prime Minister and retire from politics and was replaced by George Grenville.

Having moreover on account of his support of Pitt on the question of John Wilkes's expulsion from the House of Commons incurred the displeasure of the King, he retired for a time to his estate.

Although secret aid was given to the Corsicans it was decided not to intervene militarily and provoke a war with France, a decision made easier by the departure of the hard-line Shelburne from the cabinet.

In March 1782, following the downfall of the North ministry, Shelburne agreed to take office under Lord Rockingham on condition that the King would recognise the United States.

Shelburne's appointment by the King provoked Charles James Fox and his supporters, including Edmund Burke, to resign their posts on 4 July 1782.

One of the figures brought in as a replacement was the 23-year-old William Pitt, son of Shelburne's former political ally, who became Chancellor of the Exchequer.

Shelburne agreed to generous borders in the Illinois Country, but rejected demands by Benjamin Franklin for the cession of Canada and other territories.

Historians such as Alvord, Harlow and Ritcheson have emphasized that British generosity was based on Shelburne's statesmanlike vision of close economic ties between Britain and the United States.

The concession of the vast trans-Appalachian areas was designed to facilitate the growth of the American population and create lucrative markets for British merchants, without any military or administrative costs to Britain.

In April 1783 the Opposition forced Shelburne's resignation, and the new coalition government selected The Duke of Portland as Prime Minister until its fall in December that same year.