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,
Lawrence Dundas, 1st Earl of Zetland Lawrence Dundas, 1st Earl of Zetland Lawrence Dundas, 1st Earl of Zetland (10 April 1766 – 19 February 1839) was a British politician who sat in the House of Commons from 1790 to 1820 when he was raised to the peerage. Dundas was the son of Thomas Dundas, 1st Baron Dundas and was born in Westminster on 10 April 1766. He was educated at Harrow and was admitted at Trinity College, Cambridge. He married Harriet Hale, one of the twenty-one children of General John Hale and his wife Mary Chaloner, by whom he had three sons and four daughters. Dundas