In the mid-17th century, messianic fervor was widespread in the Jewish and Christian worlds -- not unlike today, when over 40% of Americans believe that Jesus will return to Earth during their lifetimes. Animated by historical unrest, and the messianic doctrines of the Kabbalah (both of which came to a head in 1648, both the time that the Thirty Years War ended in Europe, and a year prophesied for the coming of the messiah), the Jewish community was ripe for redemption. Along came Sabbetai Zvi, an idiosyncratic, possibly bipolar mystic from Smyrna (now part of Turkey). Zvi had grandiose ideas of himself, but was generally regarded as an eccentric until 1665, when he met with Nathan of Gaza, a brilliant Kabbalist who became Sabbetai's prophet and publicist.
Within twelve months, Sabbetai Zvi counted among his followers over one third of the European Jewish community. People left their homes, sold their belongings, and awaited the reconquest of the Holy Land. Entire communities were overturned, with Sabbatean leaders replacing traditional ones. In fulfillment of Kabbalistic prophecies, fast days were turned to feast days, and certain ritual laws annulled. Indeed, not to believe in the messiah, Sabbetai Zvi, was regarded, in many communities, as a lack of faith.
All of this attention did not escape the notice of worldly leaders, and when Sabbetai arrived in Constantinople in 1666, he was promptly arrested by the Turkish sultan. At first, Sabbetai lived a lavish life in his "imprisonment" in a castle, receiving visitors and carrying himself like the king he was heralded to be. However, things soon turned sour, and Sultan Mehmet IV did not like this peculiar Jew pretending to be king. Under duress, Sabbetai Zvi converted to Islam on September 16, 1666.
For most Jews, the conversion of the Messiah came as a terrible shock, instantly dashing their hopes of redemption. But for a considerable minority, it was all part of the plan. Some of Sabbetai's faithful converted to Islam themselves, while maintaining their Judaism secretly. Others, while not converting, maintained their secret faith in Sabbetai Zvi -- a tradition which lasted in some families for hundreds of years. These "believers" (ma'aminim in Hebrew) were relentlessly persecuted by mainstream rabbinic authorities, but they were never quite erased. As late as the last century, they still existed, either as crypto-Muslims in Turkey, or hidden Sabbateans in other communities.
The most colorful aspect of these secret Jewish heretics was their abolition of Jewish ritual laws, especially those around sexuality. Some of the more radical ones would convene on special holidays to engage in orgiastic behavior and sexual rituals. Others would eat specially treif meals of lamb cooked in milk -- scholars have published the recipes. The idea behind these practices wasn't hedonism -- remember, heretics are believers, not sinners -- but rather the belief that since the messiah has come, certain laws have been abolished. And what better way to prove your faith than to deliberately violate the laws of the pious?
Today, hardly anyone knows about Sabbetai Zvi. The traditional saying used in connection with villains is yemach shmo -- may his name be blotted out -- and it often works. But just last Spring, I was talking with an Egged bus driver in Jerusalem, and he described himself as "from Salonika," a code-word for the secret followers of Sabbetai Zvi. I looked him dead in the eye, and asked him (in Hebrew) if he meant what I thought he meant. He told me that he did.