[1] Salisbury was returned to Parliament for Great Bedwyn in 1774, a seat he held until 1780, and briefly represented Launceston and Plympton Erle in 1780.

He served as Colonel of the Hertfordshire Militia in home defence during the War of American Independence.

To help his discharged men re-enter civilian life at the end of the war, he employed 200 of them on the improvements he was making to his Hatfield estate.

[6] Lord Salisbury married Lady Emily Mary, daughter of Wills Hill, 1st Marquess of Downshire, on 2 December 1773.

The couple had four children: Lord Salisbury died in June 1823, aged 74, and was succeeded by his only son, James.