Earl of Londonderry extinct on the death of his great-grandson, the fourth Earl, in 1714. The second creation came in 1726 in favour of the soldier and politician Thomas Pitt, 1st Baron Londonderry. He had already been created Baron Londonderry in 1719 and was made Viscount Gallen-Ridgeway at the same time as he was granted the earldom, also in the Peerage of Ireland. He was the husband of Lady Frances Ridgeway, daughter and heiress of the fourth Earl of the first creation. A member of the prominent Pitt family, he was the uncle of William Pitt, 1st Earl of Chatham. His younger son,
Richard Grosvenor, 1st Earl Grosvenor 1758 he declared himself in favour of the Pitt–Newcastle ministry and following this he was created Baron Grosvenor in 1761. However, when the Tory Earl of Bute became Prime Minister the following year, Grosvenor changed his allegiance. Then, when Pitt was returned to power in the Chatham Ministry of 1766–68, Grosvenor returned to support him. During the 1770s he supported Lord North during the American War of Independence. He voted against Fox's India Bill in 1783 and was rewarded by William Pitt the Younger with title of Earl Grosvenor the following year. Otherwise, Grosvenor was interested in the acquisition of