Stephen founded the UK Holocaust Centre in Nottinghamshire, England and cofounded the Aegis Trust for the prevention of crimes against humanity and genocide. He was also the inaugural Chairman of the Holocaust Memorial Day Trust, which runs the National Holocaust Memorial Day in the United Kingdom. In 2009, Holocaust Memorial Day included over five hundred public memorial events.
Stephen is involved in memorial projects around the world. He was the project director responsible for the creation of the Kigali Memorial Centre in Rwanda and provided consultation for the Cape Town Holocaust Centre, where he still serves as a trustee.