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,
Hester Pitt, Countess of Chatham over twenty years as a friend of her brothers, on 16 November 1754 at her home in Argyle Street, London. They spent their ten-day honeymoon at West Wickham, Kent. The marriage was a happy one and the couple moved to a house in Hayes, Kent in 1756. They had five children: On 4 December 1761, she was created Baroness Chatham, of Chatham, in the County of Kent, with remainder to her sons by William Pitt, who was later created Earl of Chatham in 1766. Hester Pitt, Countess of Chatham Hester Pitt, Countess of Chatham, 1st Baroness Chatham (; 8 November