The Sabbateans (or Sabbatians) were a variety of Jewish followers, disciples, and believers in Sabbatai Zevi (1626–1676),
a Sephardic Jewish rabbi and Kabbalist who was proclaimed to be the Jewish Messiah in 1666 by Nathan of Gaza.
Vast numbers of Jews in the Jewish diaspora accepted his claims, even after he outwardly became an apostate due to his forced conversion to Islam in the same year. Sabbatai Zevi's followers, both during his proclaimed messiahship and after his forced conversion to Islam, are known as Sabbateans. Part of the Sabbateans lived on until well into 21st-century Turkey as descendants of the Dönmeh.
Sabbatai Zevi was a Sephardic ordained rabbi from Smyrna (now İzmir, Turkey). A kabbalist of Romaniote origin, Zevi, who was active throughout the Ottoman Empire, claimed to be the long-awaited Jewish Messiah. He was the founder of the Sabbatean movement, whose followers subsequently were to be known as Dönmeh "converts" or crypto-Jews.
History of the Jews in the Ottoman Empire
In February 1666, upon arriving in Constantinople, Sabbatai was imprisoned on the order of the grand vizier Köprülüzade Fazıl Ahmed Pasha; in September of that same year, after being moved from different prisons around the capital to Adrianople (the imperial court's seat) for judgment on accusations of fomenting sedition, Sabbatai was given by the Grand Vizier, in the name of the Sultan of the Ottoman Empire, Mehmed IV, the choice of either facing death by some type of ordeal, or of converting to Islam. Sabbatai seems to have chosen the latter by donning from then on a turban. He was then also rewarded by the heads of the Ottoman state with a generous pension for his compliance with their political and religious plans.
Sabbatai's conversion to Islam was extremely disheartening for the world's Jewish communities. In addition to the misery and disappointment from within, Muslims and Christians jeered at and scorned the credulous and duped Jews.
In spite of Sabbatai's apostasy, many of his adherents still tenaciously clung to him, claiming that his conversion was a part of the Messianic scheme.