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,
Earl of Northumberland Earl. The heiress to the vast Percy estates married the Duke of Somerset; and her granddaughter married a Yorkshire knight, Sir Hugh Smithson, who in 1766 was created the first Duke of Northumberland and Earl Percy, and it is their descendants who now represent the famous old house. The current duke lives at Alnwick Castle and Syon House, just outside London. <section end=1416/> Various references use at least three different sequences of numbers for the Earls; the ones shown here are those used in the individual articles on the 12 Earls. The major difference arises from the question of whether