In the late 7th century most of Crimea fell to the Khazars. In the 12th century, Rabbi
Yehuda haLevi wrote a philosophical work known as the
Kuzari, in which he placed a learned Jew in a long discussion with the Khazar king, who was searching for the religion he would take up. According to
Kuzari and certain other written sources, some or all of his people followed him into Judaism. In the 20th century, Hungarian Jewish author
Arthur Koestler suggested that
Ashkenazi Jews descended from this episode. Since then, this theory has reemerged, including by antisemites who seek to deny continuity between ancient Jews with modern Jewish populations. In 2013, Professor
Shaul Stampfer of the history department of the
Hebrew University of Jerusalem, argued that Kuzari was never intended to be a true description of the events but merely an allegory using the supposed discussion to explain Jewish philosophy. According to Stampfer, there are no Jewish graveyards, buildings, writings or references in the writings of others to suggest that there was ever any significant Jewish community among the Khazars or their leadership. However, Stampfer's assessment regarding a lack of writings is contradicted by numerous other scholars who have cited wide-ranging medieval documents, some written contemporaneous with Khazaria's existence, beginning in the 860s, that claimed that the conversion was widespread, whether among the ruling classes or the population at large. During the period of Khazar rule, some degree of intermarriage between Crimean Jews and Khazars could have occurred, but suggestions that the Krymchaks absorbed numerous Khazar refugees during the decline and fall of the Khazar kingdom (or during the Khazar
successor state, ruled by
Georgius Tzul, centered in
Kerch), seem to be fanciful. It is known that
Kipchak converts to Judaism existed, and it is possible that from these converts the Krymchaks adopted their distinctive language. In times when the Crimea belonged to the
Byzantine Empire and after then, waves of
Byzantine Jews settled there. These newcomers were in most cases merchants from Constantinople and brought with them Romaniote Jewish practices (Bonfil 2011). The
Mongol conquerors of the
Pontic–Caspian steppe were promoters of religious freedom, and the
Genoese occupation of southern Crimea (1315–1475) saw rising degrees of Jewish settlement in the region. The Jewish community was divided among those who prayed according to the
Sephardi, Ashkenazi and
Romaniote rites. In 1515 the different traditions were united into a distinctive Krymchak prayer book, which represented the Romaniote rite by Rabbi Moshe Ha-Golah, a
Chief Rabbi of
Kiev, who had settled in Crimea. In the 18th century the community was headed by David Ben Eliezer Lehno (d. 1735), author of the introduction to the "Kaffa" rite prayer book and
Mishkan David ("Abode of David"), devoted to Hebrew grammar. He was also the author of a monumental Hebrew historical chronicle,
Devar sefataim ("Utterance the mouth"), on the history of the Crimean Khanate. == Notable people ==