Chatham House Chatham House The Royal Institute of International Affairs, commonly known as Chatham House, is a not-for-profit and non-governmental organisation based in London whose mission is to analyse and promote the understanding of major international issues and current affairs. It is the originator of the Chatham House Rule and takes its name from the building where it is based, a Grade I listed 18th-century house in St James's Square, designed in part by Henry Flitcroft and occupied by three British prime ministers, including William Pitt, 1st Earl of Chatham. In the University of Pennsylvania’s rankings (announced in January 2017) for their
Hester Pitt, Countess of Chatham Hester Pitt, Countess of Chatham Hester Pitt, Countess of Chatham, 1st Baroness Chatham (; 8 November 1720 – 9 April 1803), who was Baroness Chatham in her own right, was the wife of William Pitt (the Elder), 1st Earl of Chatham, who was Prime Minister of Great Britain from 1766 to 1768. The sister of George Grenville, who was Prime Minister from 1763 to 1765, she was also the mother of Prime Minister William Pitt the Younger and a niece of the noted Whig politician Richard Temple, 1st Viscount Cobham, who had served as her husband's mentor. Chatham and Elizabeth