David served as a teacher in the UK state system in the 1970s and 80s before joining the university sector as a teacher educator in 1986. His doctoral study focused on the development of programmes to enable teachers to lead change in their schools. In 1996 he joined the Faculty of Education at Cambridge where he was able to continue his interest in teacher leadership. He was one of the founders of the Leadership for Learning group at the Faculty of Education. By building partnerships with a local education authority, schools and teachers, David was able to develop the HertsCam Network, which subsequently became an independent, teacher-led organisation. It is now a registered charity which continues to support school and teacher development.