He served in only two high offices during his lifetime (prime minister and leader of the House of Lords) but was nonetheless very influential during his one and a half years of service.

He was brought up at the family's lavish home of Wentworth Woodhouse near Rotherham[1] in Yorkshire, and became Viscount Higham on his elder brother's death in 1739.

[2] During the Jacobite rising of 1745, his father, Lord Malton, made him a colonel and organised volunteers to defend the country against the "Young Pretender".

He did this without parental consent and Cumberland wrote to Lord Malton, saying that his "zeal on this occasion shows the same principles fix't that you yourself have given such strong proofs of".

[3]: 3  Higham wrote to his father that Cumberland "blamed me for my disobedience, yet as I came with a design of saving my King and country...it greatly palliated my offence".

[3]: 8  When in Herrenhausen, Hanover, he met George II of Great Britain and made an impression: the King told Malton's uncle Henry Finch that he had never seen a finer or a more promising youth.

[3]: 10 Rockingham's maiden speech was on 17 March 1752 in support of the bill which disposed of Scottish lands confiscated in the aftermath of the Jacobite rising of 1745.

Rockingham hired James Stuart, of whom he was a patron,[9] to paint portraits of William III and George II for the club rooms.

Rockingham wrote to Newcastle: ...without flattery to your Grace, I must look and ever shall upon you and your connections as the solid foundations on which every good which has happened to this country since the [Glorious] Revolution, have been erected.

[3]: 45 Over the next several years, Rockingham gradually became the leader of those of Newcastle's supporters who were unwilling to reconcile themselves to the premierships of Bute and his successor, George Grenville.

Also at this time, Edmund Burke, the Irish statesman and philosopher, became his private secretary and would remain a lifelong friend, political ally and advisor until Rockingham's death from influenza in 1782.

[3]: 113  However Rockingham also passed the Declaratory Act, which asserted that the British Parliament had the right to legislate for the American colonies in all cases whatsoever.

John Michell, vicar to Rockingham's kinsman, fellow leading politician and keen advocate of colonists' rights Sir George Savile.

[12] Rockingham wrote to Augustus Keppel on 3 November 1779, saying that he believed the war against America could not be won, that the government was corrupt but not unpopular, and that the longer this continued the greater the danger to the liberties and the constitution of Britain: "Perhaps a total change of men and measures, & system in the Government: of this country might have effect on the councils of some foreign countries...who might think that it was no longer a Court system to combat, but that the whole nation would unite & make the utmost efforts".

I have no doubt that you will take it in good part, that his old friends, who were attached to him by every tie of affection, and of principle, and among others myself, should look to you, and should not think it an act of forwardness and intrusion to offer you their services".

The Whig party further split over the French Revolution, with Burke writing to Fitzwilliam on 4 January 1797: "As to our old friends, they are so many individuals, not a jot more separated from your Lordship, than they are from one another.

They carried into politics the same high principles of virtue which regulated their private dealings, nor would they stoop to promote even the noblest and most salutary ends by means which honour and probity condemn.

Such men were Lord John Cavendish, Sir George Savile, and others whom we hold in honour as the second founders of the Whig party, as the restorers of its pristine health and energy after half a century of degeneracy.