In 1756, Jacob Frank, an Ottoman Jew who had returned to the Poland of his birth, was discovered leading a group of fellow travelers in a suspect religious service. At the request of the local rabbis, Polish authorities arrested the participants. Jewish authorities contacted the bishop in whose diocese the service had taken place and argued that since the rites of Frank's followers involved the practice of magic and immoral conduct, both Jews and Christians should condemn them and burn them at the stake. The scheme backfired, as the Frankists took the opportunity to ally themselves with the...