The Royal Society of Medicine.

With a membership of just over 17 500 the Royal Society of Medicine is the largest medical society in Britain. Its ancestor, the Medical and Chirurgical Society of London, was founded in 1805 when a band of malcontents seceded from the Medical Society of London. By the charter of 1834 the Society became the Royal Medical and Chirurgical Society, which amalgamated with over a dozen other societies to create the Royal Society of Medicine in 1907. It occupies number 1 Wimpole Street, a monumental building that has been redeveloped for the Society's bicentenary in 2005.