of Bar Kokhba's revolt by the emperor Hadrian, those Jews who were not executed were exiled to the Crimean peninsula. The late classical era saw great upheaval in the region as Crimea was occupied by Goths, Huns, Bulgars, Khazars, and other peoples. Jewish merchants such as the Radhanites began to develop extensive contacts in the Pontic region during this period, and probably maintained close relations with the proto-Krymchak communities. Khazar dominance of Crimea during the Early Middle Ages is considered to have had at least a partial impact on Krymchak demographics. Middle Ages 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. A belief arose that his people followed him into Judaism. In the 20th century, a Jewish writer by the name of 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. 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