For 200 years, "The Lock" was well known to the London public. It accorded high status to its medical staff, it was governed by aristocrats and evangelists and received the patronage of royalty. It was closed at the start of the NHS in the belief that the scourge of venereal disease had been conquered. It is now largely forgotten, although the vicissitudes through which it passed have interesting parallels to recent experience. The Committee records, which have been preserved, form the basis of this account. The book is intended for those with a concern for the changing medical scene, and it should be of interest to those interested in the history of modern medicine and its interaction with charity.