He died without male issue and was succeeded by his nephew, the fifth Earl. He was the son of the Hon. George Vere Hobart, second son of the third Earl. Lord Buckinghamshire briefly represented St Michael's in Parliament. In 1824 he assumed by Royal license the additional surname of Hampden. He died childless and was succeeded by his younger brother, the sixth Earl. He was a clergyman. In 1878 he assumed by Royal license the additional surname of Hampden. He was succeeded by his grandson, the seventh Earl. He was the second but only surviving son of Frederick John Hobart-Hampden, Lord Hobart, second son of the sixth Earl. Lord Buckinghamshire served briefly as a Lord-in-Waiting (government whip in the House of Lords) in 1895 in the Liberal administration of the Earl of Rosebery. He married Georgiana Wilhelmina Haldane-Duncan-Mercer-Henderson, daughter of the Hon. Hew Adam Dalrymple Hamilton Haldane-Duncan-Mercer-Henderson and Edith Isabella Mercer-Henderson. In 1903 Lord Buckinghamshire assumed by Royal license the additional surnames of Mercer-Henderson.
On his death the titles passed to his only son, the eighth Earl. He was Deputy Chairman of Committees in the House of Lords and a Deputy Speaker of the House of Lords. In 1938 he assumed by Royal license the surname of Mercer-Henderson only in lieu of Hobart-Hampden-Mercer-Henderson. He never married and on his death in 1963 the line of the second son of the sixth Earl failed. He was succeeded by his second cousin, the ninth Earl. He was the grandson of the Hon. Charles Edward Hobart-Hampden, fourth son of the sixth Earl. He was childless and was succeeded by his second cousin once removed, the tenth Earl and (as of 2007) present holder of the titles. He is the great-grandson of the Hon. George Augustus Hobart-Hampden, fifth son of the sixth Earl (and the eldest from his second marriage).