In Arabic he wrote his philosophical work, called in the Hebrew translation Sepher ha-Kuzari, a defence of revelation as against non-Jewish philosophy and Qaraite doctrine.
Not even the Qaraite schism was able to break the power of the geonim.
The most clearly marked distinctions are between Spanish, French, German, Italian, Maghrebi, Greek, Syrian (including Egyptian), Yemenite, Persian and Qaraite hands.
Pop. (1897), 12,961, consisting of Tatars, Armenians, Greeks, Qaraite Jews, and about 200 so-called Krymchaki, i.e.
Among the motley population of Russians, Tatars, Armenians, Germans and Greeks are several hundred Qaraite Jews.