We already know enough about the Khazars to say that Koestler's fantasy has no basis in fact. For example, we know that in the Khazar kingdom, there were a total of seven judges: two for Muslims, two for the Khazars, who decide according to the Torah, two for Christians, who decide according to the Gospel, and one for the Slavs, Russes and other pagans whose judgement was according to natural law, according to the dictates of reason. We already know that during the reign of Romanus I Lepakanos, in 933 CE (322 AH), "large numbers of Jews left the Byzantine Empire, to take refuge with the Khazars." The information cited here on the Khazars comes from Al-Masudi, the Arab historian, writing contemporaneously with these events.
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