The Survey of London - 100 years old in 1994 - traces its origins to the campaigning zeal of the 1890s when C.R. Ashbee and a group of conservationists set up the Watch Committee to campaign against the demolition of historic buildings, such as the Trinity Hospital (1695) in Mile End Road. Out of this grew what Osbert Lancaster described as the great enterprise, creating an inventory of all London's historic buildings as an aid to their protection. That massive undertaking still continues and this work traces the vicissitudes of the Survey over the last 100 years. It describes an organization that has been in the forefront of the conservation movement and whose work has been hailed as the London conservationist's Bible.