Until his death in 2015, S. Barry Cooper was Professor of Mathematical Logic at the University of Leeds. He was both a leading figure in the theory of Turing computability, and a noted advocate of multidisciplinary research, especially in connection with the theoretical and practical limits of the computable. As President of Computability in Europe, he was responsible for many international conferences. He chaired the Turing Centenary Committee, and edited the prize-winning critical edition of Turing's publications: Alan Turing: His Work and Impact.