This article explores changes in policy and practice in children’s services over the past 40 years and discusses the thinking that has underpinned them. Together with a special journal supplement introduced by John Simmonds, it marks the 40th anniversary of BAAF (the British Association for Adoption and Fostering), which was founded in 1980 and in 2015 joined the long-established Coram charity to form CoramBAAF Adoption & Fostering Academy.