Upon arriving in Constantinople in February 1666, Sabbatai was imprisoned on the order of the grand vizierKöprülüzade Fazıl Ahmed Pasha. In September of that same year, after being moved from different prisons around the capital to the imperial courts' seat in Adrianople (now Edirne), he was judged on accusations of fomenting sedition. Sabbatai was given the choice of either facing death by some type of ordeal or of converting to Islam by the Grand Vizier representing Sultan Mehmed IV. He seems to have chosen the latter course, donning a turban from that time on. The heads of the Ottoman state then rewarded him with a generous pension for complying with their political and religious plans.[7] About 300 families who followed Zevi also converted to Islam and became known as Dönme.[8]
Subsequently, the Ottomans banished him twice, first to Constantinople, and, when he was heard singing Psalms with Jews, to a small town known today as Ulcinj in present-day Montenegro. He later died in isolation.[9][10]
^Scholem, Sabbatai Sevi: The Mystical Messiah: 1626–1676, pp. 103–106 has a whole discussion of the historical probabilities that he was really born on the 9th of Av, which according to Jewish tradition is the date of the destruction of both Temples and is also the date 'prescribed' in some traditions for the birth of the Messiah.
^Scholem, op. cit., p. 111, mentions, among other evidence of Sabbatai's early rabbinic training and semikhah by Rabbi Joseph Eskapha of his native town of Smyrna: "According to the testimony of Leib b. Ozer, the notary of the notary of the Ashkenazi community of Amsterdam ..., Sabbatai was eighteen years old when he was ordained a hakham." Scholem also writes, in the previous sentence: "Thomas Coenen, the Protestant minister serving the Dutch congregation in Smyrna, tells us ... that he received the title hakham, the Sephardi honorific for a rabbi, when still an adolescent."
^Wigoder, Geoffrey (1972). Jewish Art and Civilization. p. 44.