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
Earl of Chatham her husband had wished to remain a member of the House of Commons. Their second son was William Pitt the Younger, who became the country's youngest Prime Minister in 1783, at the age of 24. Their eldest son, John Pitt, inherited the earldom and viscountcy in 1778 and the barony in 1803. Upon his death in 1835, all three titles became extinct. The second creation of this title came in 1761 in favour of Lady Hester Pitt; the first creation was for John Campbell, 2nd Duke of Argyll and hence the Duke of Argyll. Earl of Chatham Earl of Chatham,