is Reader in Modern Jewish Studies in the University of London and Director of the Centre for Hebrew and Jewish Studies at the School of Oriental and African Studies. An authority on Jews in the Islamic world, marginal Jewish communities and Judaizing movements, his works include The Road to Redemption: The Jews of the Yemen, 1900-1950 (1979); Judaising Movement (with Emanuela Trevisan-Semi, 2002); and The Last Tribes of Israel: The History of a Myth (2002)