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,
John Pitt, 2nd Earl of Chatham recalled in disgrace. His appearance before a parliamentary enquiry did him no favours, particularly when it emerged that he had presented the King with a private memorandum which ought to have gone to the Secretary of State for War first. Spencer Perceval's government withdrew its support from Chatham and he was forced to resign from the Ordnance in May 1810. Chatham's political and military reputation was ruined. A poem circulated making fun of his inactivity and the lack of co-operation between the army and navy: Chatham did not serve actively again, but was promoted to full General in January 1812.