Rockingham was born Charles Watson-Wentworth in May 1730 into an aristocratic family (the first Prime Minister to have been born at a time when the office existed). He was educated at Westminster School, briefly serving as a volunteer during the 1745 Jacobite rising.  After that, Rockingham set out on the customary Grand Tour of Europe. In May 1751, his father died, and Rockingham inherited his father’s estates and hereditary peerage, becoming Lord Rockingham.

Though shy, and not a particularly notable speaker, Rockingham had a talent for party organisation. During the 1750s, he formed the Rockingham Club of Whigs, which soon had over 150 members. Rockingham was also appointed to the royal household, as Lord of the Bedchamber in 1752.

Rockingham resigned from the royal household in November 1762. As a Whig, he disagreed with George III’s more assertive role in politics, and soon most his fellow Whigs joined him in opposition.

In 1765, after the weak premierships of Bute and Grenville, George III looked for a more stable ministry, and though he would have preferred his uncle, the Duke of Cumberland, to be Prime Minister, he ultimately looked for a Whig leader to form a government. With the Duke of Newcastle too elderly and the Duke of Devonshire having died a few months before, Rockingham was the de facto Whig leader. After sensitive negotiations, Rockingham agreed to form a government in July 1765, despite his total lack of ministerial experience.

At this time, to what extent Rockingham intended to be Prime Minister is open to question. Cumberland was still influential over the government. Cabinet meetings were held in Cumberland’s presence in Windsor or at his London house. But Cumberland died in October 1765, leaving Rockingham in full control.

Rockingham was criticised for appointing several members of Cabinet who were from the Jockey Club. Rockingham adored horseracing and a painting of his horse Whistlejacket by George Stubbs, can be seen in the National Gallery.

Rockingham, like the Prime Ministers before and after him, grappled with the legacy of the Seven Years’ War, and the increasingly disagreeable situation in America. He repealed the Stamp Act, which had caused such outrage. However, his government also passed the Declaratory Act making clear that Parliament ruled in America, and could overrule any American body, which provoked further anger. Fears that the ministry was not taking the crisis seriously enough supposedly gave rise to the complaint that ‘the Ministry’s asleep and the Minister’s Rocking-em.’

Ultimately, the arrangement proved unstable. Rockingham did not have much support in the Commons, and an attempt to reach out to William Pitt backfired, when Pitt suddenly declared his opposition to the ministry. The King soon concluded that the Rockingham ministry needed to be replaced. He got an excuse when Rockingham failed to make proper financial arrangements for his brothers. Rockingham was dismissed on 30 July 1766.

For the next sixteen years Rockingham maintained a group of political supporters in parliament called the Rockingham Whigs, a precursor of the modern party system. It was here that he made his biggest contribution to history. He increasingly spoke up in the House of Lords, overcoming his shyness. He counselled moderation in America, and had he been listened to, much pain might have been avoided. In 1778, Rockingham called for the immediate granting of American independence and urged conciliation.  When Lord North fell in 1782, Rockingham was the obvious man to take over as Prime Minister.

When Rockingham came to power, his government was a ‘clean sweep’ with an entirely new selection of ministers. He immediately changed the apparatus of government, replacing the antiquated positions of Northern and Southern Secretaries with a clearly defined Home Secretary and Foreign Secretary, with Charles James Fox and Lord Shelburne being the first holders of these offices.

The Rockingham government declared an end to hostilities in America and began negotiations with the American colonists. Though fighting continued between British forces and the French, Spanish, and Dutch, there would be no more battles against the Americans.

Rockingham was quite ill by then, and much business was conducted by Shelburne instead. Though, several pieces of legislation were passed to reduce corruption (which had long been a Whig demand), preventing government funds being spent on elections, excluding government officials from the Commons, and disenfranchising revenue officers. Legislation was also passed providing internal self-government for Ireland (though this would later be repealed by the Union of 1800).

Rockingham died on 1 July 1782, after a second premiership of just 96 days. Overall, he was Prime Minister for only one year and 113 days.

Rockingham married Mary Bright in 1752, they had no children.