For members of the SSBP, Bill will also be warmly remembered for all his work in helping to found the Society. Throughout the early decades of the 20th century, although the genetic basis of more and more developmental disorders was beginning to be identified, individuals with intellectual disabilities still tended to be regarded, and treated, as if they were a homogeneous group. To counter this view, Bill, with Greg O’Brien, Jim Harris, Tom Oppé, Martin Bax and others in the 1980’s, began to highlight the importance of recognising the very different cognitive and behavioural profiles, needs, and outcomes of children with a range of developmental and genetic disorders. Together they were instrumental in setting up the SSBP in 1987, with the goal of fostering research and developing new genetic and scientific approaches for improving clinical practice and interventions for individuals with many different behavioural and genetic phenotypes. By 1991, Bill and his colleagues had organised the first SSBP conference in London; twenty-three annual meetings, spanning much of the world, have followed to date. In 1996, Bill and Greg O’Brien edited the book “Behavioural Phenotypes”, with contributions from several other SSBP members, summarising advances in the identification, understanding and treatment of individuals with genetic and developmental disorders.