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,
William Pitt, 1st Earl of Chatham from 1756 to 1761 (with a brief interlude in 1757), during the Seven Years' War (known as the French and Indian War in the United States). He again led the ministry, holding the official title of Lord Privy Seal, between 1766 and 1768. Much of his power came from his brilliant oratory. He was out of power for most of his career and became well known for his attacks on the government, such as those on Walpole's corruption in the 1730s, Hanoverian subsidies in the 1740s, peace with France in the 1760s, and the uncompromising policy towards the American colonies