Khazaria and Caspian Jews

Origins. The Khazars were a Turkic$$¹ people who originated in Central Asia. The early Turkic tribes were quite diverse, although it is believed that reddish hair was predominant among them prior to the Mongol conquests. In the beginning, the Khazars believed in Tengri shamanism, spoke a Turkic language, and were nomadic. Later, the Khazars adopted Judaism, Islam, and Christianity, learned Hebrew and Slavic, and became settled in cities and towns thruout the north Caucasus and Ukraine. The Khazars had a great history of ethnic independence extending approximately 800 years from the 5th to the 13th century.
The earliest history of the Khazars in southern Russia, prior to the middle of the 6th century, is hidden in obscurity. From about 550 to 630, the Khazars were part of the Western Turkish Empire, ruled by the Celestial Blue Turks (Kök Turks). When the Western Turkish Empire was broken up as a result of civil wars in the middle of the 7th century, the Khazars successfully asserted their independence. Yet, the Kök kaganate under which they had lived provided the Khazars with their system of government. For example, the Khazars followed the same guidelines as the Kök Turks regarding the succession of kings.
Political power. At its maximum extent, the independent country of Khazaria included the geographic regions of southern Russia, northern Caucasus, eastern Ukraine, Crimea, western Kazakhstan, and northwestern Uzbekistan. Other Turkic groups such as the Sabirs and Bulgars came under Khazar jurisdiction during the 7th century. The Khazars forced some of the Bulgars (led by Asparukh) to move to modern-day Bulgaria, while other Bulgars fled to the upper Volga River region where the independent state of Volga Bulgharia was founded. The Khazars had their greatest power over other tribes in the 9th century, controlling eastern Slavs, Magyars, Pechenegs, Burtas, North Caucasian Huns, and other tribes and demanding tribute from them. Because of their jurisdiction over the area, the Caspian Sea was named the "Khazar Sea", and even today the Azeri, Turkish, Persian, and Arabic languages designate the Caspian by this term (in Turkish, "Hazar Denizi"; in Arabic, "Bahr-ul-Khazar"; in Persian, "Daryaye Khazar")
In addition to their role in indirectly bringing about the creation of the modern Balkan nation of Bulgaria, the Khazars played an even more significant role in European affairs. By acting as a buffer state between the Islamic world and the Christian world, Khazaria prevented Islam from significantly spreading north of the Caucasus Mountains. This was accomplished thru a series of wars known as the Arab-Khazar Wars, which took place in the late 7th and early 8th centuries. The wars established the Caucasus and the city of Derbent as the boundary between the Khazars and the Arabs. 

Under the leadership of kings Bulan and Obadiah, the standard rabbinical form of the Jewish religion spread among the Khazars. King Bulan adopted Judaism in approximately the year 838, after supposedly holding a debate between representatives of the Jewish, Christian, and Muslim faiths. The Khazar nobility and many of the common people also became Jews. King Obadiah later established synagogues and Jewish schools in Khazaria. The books of the Mishnah, Talmud, and Torah thus became important to many Khazars. Saint Cyril came to Khazaria in 860 in a Byzantine attempt to convert the Khazars to Christianity, but he was unsuccessful in converting them away from Judaism. He did, however, convince many of the Slavs to adopt Christianity. By the 10th century, the Khazars wrote using Hebrew letters. The major Khazar Jewish documents from that period were written in the Hebrew language. The Ukrainian professor Omeljan Pritsak estimated that there were as many as 30,000 Jews in Khazaria by the 10th century. In 2002, the Swedish numismatist Gert Rispling discovered a Khazar Jewish coin.