Lord Stanhope's grandson, the third Earl, was a politician and scientist, known as "Citizen Stanhope" because of his sympathy for the French revolution. He was succeeded by his son, the fourth Earl. He represented several constituencies in the House of Commons but is chiefly remembered for his involvement in the Kaspar Hauser case. His son, the fifth Earl, was a Tory politician and historian. He served as Under-Secretary of State for Foreign Affairs and also published a biography on William Pitt the Younger. On his death the titles passed to his son, the sixth Earl. He was a Conservative politician and served briefly as a Lord of the Treasury from 1874 to 1875 in Benjamin Disraeli's second administration. Lord Stanhope was also Lord Lieutenant of Kent.
His son, the seventh Earl, was also a Conservative politician and notably served as President of the Board of Education, as Leader of the House of Lords and as First Lord of the Admiralty. In 1952 Lord Stanhope succeeded his distant relative Edward Henry Scudamore-Stanhope, 12th Earl of Chesterfield, as thirteenth Earl of Chesterfield and 13th Baron Stanhope. However, he never applied for a writ of summons to the House of Lords in these titles and continued to be known as the Earl Stanhope. On his death in 1967 the earldoms of Stanhope and Chesterfield and barony of Stanhope became extinct. However, he was succeeded in the viscountcy of Stanhope of Mahon and barony of Stanhope of Elvaston according to the special remainder by his kinsman William Stanhope, 11th Earl of Harrington.
The Heir Apparent to the Earls Stanhope used the courtesy title Viscount Mahon.
Philip Stanhope, 1st Baron Weardale, was a younger son of the fifth Earl.