Zinovy Zinik writes of traveling to Turkey to:
retrace the steps of the self-proclaimed Messiah Shabbatai Zvi, A Turkish Jew from Izmir, who, having created in 1666 an atmosphere of apocalyptic hysteria across the entire Jewish world, suddenly, after a prolonged audience with the Sultan, converted to Islam. Shocked and amazed by his conversion, thousands of adherents saw in it some mysterious and arcane act of self-sacrifice, and followed his example. Thus was created a fascinating sect of Jewish Muslims whose descendants may still be found in modern Turkey. […]
They are still known in Turkey under the pejorative name Donme, which means both converts and turncoats. The Jews accused them of apostasy, while some nationalist Turks suspected them of being Jews in disguise, those who hide the yarmulke under the fez. No wonder they eventually embraced the European Enlightenment and created a network of the best secular schools in Turkey.