It is arguable that the most brilliant single idea in wildlife conservation in the past quarter of a century has been the Red Data Books for endangered species. They are certainly the most widely known activity of IUCN, and were the brainchild of Sir Peter Scott, for many years Chairman of IUCN's Survival Service Commission and now, among many other distinctions, President of the ffPS. The first RDBs, compiled by Noel Simon for mammals and Jack Vincent for birds, were published in 1966. The amount of material available, together with the accelerating slide of so many animals towards extinction, soon made the original horse-and-buggy arrangements for compiling the RDBs out of date, and there was a serious possibility that they would cease to be regarded as the authoritative works of reference they had become. Fortunately there were sufficient concerned people to persuade WWF and IUCN into financing the Species Conservation Monitoring Unit at Cambridge (now part of the IUCN Conservation Monitoring Centre), and for the first time the RDB operation was properly housed, staffed and equipped.