Sabbatai Zevi (שַׁבְּתַאי צְבִי Shabbetai Tzvi, other spellings include Sabbatai Ẓevi, Shabbetai Ẓevi, Sabbatai Sevi, and Sabetay Sevi in Turkish) (August 1, 1626 – c. September 17, 1676 in Dulcigno (present day Ulcinj, Montenegro) was a Sephardic Rabbi and kabbalist who claimed to be the long-awaited Jewish Messiah. He was the founder of the Jewish Sabbatean movement.
At the age of forty, he was forced by the Ottoman Sultan Mehmed IV to convert to Islam. Some of his followers also converted to Islam, about 300 families who were known as the Dönmeh (aka Dönme) (converts).
Read more about Sabbatai Zevi: Early Life and Education, Influence of English Millenarianism, Claims of Messiahship, In Salonica, Cairo, and Jerusalem, Marriage To Sarah, Nathan of Gaza, Proclaimed Messiah, Spread of His Influence, In Istanbul, At Abydos (Migdal Oz), Nehemiah Ha-Kohen, Sabbatai Adopts Islam, Disillusion, Last Years, Exile and Death, Modern Followers