“…Historical Developments Although both Islam and Christianity prohibit forced conversions, these have occurred in periods of persecution, for instance as during the First Crusade in 1096, or the Almohad invasion of the Iberian Peninsula in the twelfth century. Many of these conversions were, however, temporary, and the forced converts returned to Judaism as soon as possible (Roos 2003(Roos , 2006). Yet there were also Jews who converted who remained in their new faith, some of these even becoming famous for trying to convince their former co-religionists to follow them.…”