In The Thirteenth Tribe: The Khazar Empire and Its Heritage, Arthur Koestler has again, as with his book, The Midwife Toad, undertaken an exciting and fascinating study of a plausible but quite unsubstantiated theme. The Thirteenth Tribe attempts to demonstrate that most Ashkenazic Jews are descendants of the tribe of Khazars that dominated the area now known as south central Russia in the period between the seventh and the tenth centuries A.D. Thus, most Ashkenazic Jews, in Koestler’s view, are not Semites, but Khazars. The author develops this thesis through his analysis of the rise and fall of the Khazar Empire and his interpretation of the Khazar heritage.

Khazaria, whose inhabitants were of Turkish origin, lay between the Black Sea and the Caspian Sea, stretching from the Caucasus on the South to Kiev on the north and from the Volga on the east to the Dnieper on the west, and it served as a buffer separating Byzantium, the barbarian tribes of the steppes (Bulgars, Magyars, and eventually Vikings or Russians) and the Muslims to the south and east. Khazaria protected Byzantium from barbarian attacks and in the seventh and eighth centuries prevented the Arab conquest and conversion of the southern steppes. Curiously, around 740, the Khazars converted en masse to Judaism. But what happened to the Khazars in the eleventh and twelfth centuries, after the destruction of Khazaria, remains a mystery for which Koestler claims to provide the answer. He contends that the Khazars migrated to eastern Europe, settled in Russia, Poland, Hungary, and Lithuania, and came to make up the bulk of Ashkenazic Jews.

The Khazars developed a fairly high level of civilization during the four centuries of the height of their empire. Starting as a group of fierce nomadic tribes, they settled into cities and became farmers, cattle raisers, traders, and craftsmen. They established lines of frontier fortifications that permitted for a time a stable development of the interior of Khazaria. The Khazars established hegemony over such tribes as the Bulgars, Magyars, Ghuzz, and the northwestern Slavonic tribes. Khazar armies raided Georgia to the south and the Arab Empire.

Their origin is believed to be Hun and they are spoken of as “Turks.” Koestler was convinced that they were of Turkish origin and in the fifth century A.D. emerged from the Asian steppes. The earliest accounts indicate that they were under the sovereignty, with other tribes, of Attila, and, following his death, became the major power in the region, subduing such tribes as the Sabirs, the Saragurs, the Samandars, the Balanjars, and the Bulgars. By the middle of the seventh century they controlled what the Byzantines referred to as the “Kingdom of the North.”

The major kingdoms of the region were Khazaria, Christian Byzantium, and the Muslim Caliphate. Alliances were made especially between Byzantium and Khazaria to prevent Arab conquest of eastern Europe. The Khazars bore the brunt of the Arab attacks and saved eastern Europe from the Arabs at about the same time that Charles Martel stopped the Arab thrust to conquer western Europe. From their efforts against the Muslims, the Khazars extended their domination into the Crimea and the Ukraine. By the early eighth century Khazaria was a powerful empire ruled by its Kagan (King) and able to muster armies of 100,000 and even 300,000, according to Arab sources.

Not only did the Khazars play the crucial role in the containment of the Arabs in the east, but they also were significantly involved in political struggles and intrigues within the Byzantine Empire, supporting some and opposing other Emperors or would-be Emperors. The Khazars also served as a conduit to spread Persian and Byzantine arts and crafts among the uncivilized tribes, and developed on their own a comparatively high level of civilization. Although their art and culture were derivative, they were of high quality, and the Khazars enjoyed the cosmopolitanism of urban living, focused first on the fortress of Balanjar, later on the city of Samandar, and finally on the city of Itil.

The Khazars were a fiercely independent tribe and Koestler argues that their conversion to Judaism was the result of that desire to remain independent from their Muslim and Christian neighbors. Khazaria, equaling the Byzantine and the Islamic empires in stature and military prowess, recognized that acceptance either of Christianity or of Islam would mean subordination to the authority either of the Byzantine Empire or the Caliph of Baghdad. In the midst of this dilemma they settled on a religion that would preserve Khazar independence—Judaism.

The choice in behalf of Judaism did not take place at once. As a cosmopolitan society, Khazaria contained Christians, Arabs, and Jews. There had, in fact, been a constant stream of Jewish refugees who had fled wave after wave of Byzantine persecution and torture in every century from the sixth through the tenth. Only in Khazaria could Jews find a refuge and the toleration that was lacking everywhere in the Christian world. They in turn, brought the culture and crafts of the Christian world to Khazaria and reinforced the atmosphere of toleration that existed there and that aroused the admiration of Arab visitors. In turn, the Jews of Khazaria apparently lived exemplary lives so that they were admirable models and served as an inducement for conversion.

The conversion apparently took place in two steps. The first was to a rudimentary Judaism primarily involving the Kagan, King Bulan, and the Court. Some generations after the initial conversion, there took place a far more widespread conversion or revival; rabbinic Judaism was adopted at this stage. Conversion, then, took the form of a progression. This was all documented in a letter written in the tenth century by a Khazar Kagan, Joseph, who described in detail his kingdom and the process of conversion.

The Khazar kingdom reached the zenith of its power and prestige in the eighth and early ninth centuries, maintaining a peace along its borders and throughout Khazaria. Symbolic of this prestige was the Byzantine Emperor, Leo the Khazar (775-780), named after his Khazar mother. However, by the ninth century, a cloud appeared on the Khazar horizon—Viking or Norse invaders, as they were known in the West, or Rus or Rhos, as they were known in the East.

The effects of the Viking raids on Khazaria were as devastating as they were in western Europe. The Vikings were savage pirates and plunderers who returned on a seasonal basis, establishing camps from which they launched their raids. Not only did they plunder, but they sold their stolen goods, so that they brought both piracy and trade to the areas that they raided. The Khazars and the Byzantines alternated in their relations with the Rus between agreements and wars. Eventually the Rus interbred with the peoples of the region, established permanent settlements, and became Russians.

Although the Rus concentrated their raids on the wealthier Byzantines for the first century of their forays, they took over some of the Khazar’s vassal tribes and, therefore, somewhat reduced the size of Khazaria. In the second half of the ninth century, the Khazar city of Kiev on the Dnieper became Rus property, and Kiev became the Russian capital. Khazars remained in Kiev and helped to cosmopolitanize the Russians. The Khazars also had an influence on the Magyars in the ninth and tenth centuries, providing them with a king, Arpod, founder of the Magyar’s first dynasty; and several Khazar tribes, chased out of Khazaria because of rebelliousness, also offered leadership and military competence to the Magyars as they established their kingdom to the west of Khazaria.

While the Khazars were working out their relationships with the Russians and the Magyars, the Byzantines were making treaties with the Russians and seeking to convert them to Christianity. Princess Olga of Kiev was baptized in 957, but the Russians were only converted to Greek Orthodoxy in 988 under Vladimir. In the context of improving relations between the Russians and Byzantines, Khazaria began to decline in importance and was clearly an inconvenience for Kiev and Constantinople. Throughout the tenth century, the Russians continued to encroach on Khazaria, gaining a foothold in territories previously dominated by the Khazars. Khazar control of the Slavonic tribes ended, although the heart of the Khazar Empire remained. Then, early in the eleventh century, the Byzantine-Khazar alliance was abrogated by Byzantium, the Byzantines made an alliance with the Russians, and a Byzantine-Russian army attacked and subdued Khazaria.

While the Khazars had maintained peace throughout the region, the Byzantines and the Russians could not. The downfall of Khazaria was followed by chaos as the tribes that the Khazars had pacified now began a ceaseless warfare with one another. Branches of the tribe of the Ghuzz began moving west and pushing other tribes before them, while another branch of the Ghuzz defeated the Byzantines at the Battle of Manzikert (1071), opening Asia Minor to control by the Turks. Throughout the eastern steppes, the decline of Khajaria meant the descent of the region into instability and barbarism. In those Dark Ages, a reduced and weakened Khazaria clung to life through most of the twelfth century, after which references in historical documents to the Khazar Empire cease.

Koestler has sketched what is known of the story of the Khazars with accuracy. However, having traced the rise and fall of Khazaria, Koestler next moves to a highly speculative and questionable account of what he regards to be the Khazar heritage. For example, while the significant Jewish population in Hungary during the medieval period is believed to have been of Khazar origin, Koestler suggests without proof a similar origin for other east European Jewish populations. He contends that the Black Plague in the fourteenth century swept through the former Khazar Empire devastating all of the surrounding tribes and depopulating the steppes. This accelerated the growth of barbarism and anarchy and caused a movement of peoples throughout the area. Under these pressures, the Khazars settled in Kiev, in the Ukraine and southern Russia, and in Poland. Koestler argues that many Polish and Ukranian place names derive from “Khazar” or “Zhid” (Jew). Moreover, as many Khazars moved west, many remained behind, forming Jewish settlements in the Caucasus, the Crimea, and elsewhere.

Koestler discusses at length Jewish involvement in the early history of the Polish kingdom where Jewish Khazars were welcome. The 1264 Charter of Boleslav the Pious that received confirmation in 1334 by Casimir the Great granted the Jews autonomy over their own religious, educational, and legal matters and extended to them property and occupational rights. This pattern of grants of rights to Jews was maintained and expanded under other Polish rulers. Under such favorable conditions, the movement of Khazar Jews into Poland over the centuries was considerable. There was also a major migration of Khazar Jews into Lithuania, Hungary, and the Balkans. In fact, Koestler argues that “during the middle ages the majority of those who professed the Judaic faith were Khazars.”

Koestler discusses what he believes to be other results of Khazar activities. The shtetl, or Jewish rural community or town, was a Khazar tradition. Moreover, some trades became a Jewish monopoly as a consequence of the Khazar heritage. Koestler speculates that gefilte fish, a Jewish delicacy, may have been a Khazar legacy. More importantly, however, Koestler contends that the number of Jews of western Europe in the thirteenth century and after that were persecuted by Christians and forced to flee to eastern Europe was too few numerically to make up the large Jewish populations of Poland, Lithuania, Russia, Hungary and other states of eastern Europe. The bulk of those populations was of Khazar origin. Thus the eastern European Jewish populations were made up of Khazars moving west and not of persecuted western European Jews moving east. Additionally, the Jewish language of Yiddish, Koestler argues, had a Khazar origin to which German, Polish, and other languages were added. Finally, Koestler lapses into the ridiculous in his speculations as he argues that the physical differences between the Sephardic Jews and the Ashkenazic Jews represent the biological distinctions between Sephardic Semites and Ashkenazic Khazars. Consequently, the traditional Semitic nose. If this sounds far-fetched, it is. Altogether, therefore, Koestler has convinced himself that the bulk of European Jews are of Khazar and not of Semitic origin.

Koestler recognizes the danger of denying the Semitic heritage of the European Jews. Since the modern State of Israel contains many European Jews, his book is tantamount to supporting the Arab argument that Israel has no right to exist. Therefore, Koestler adds a section to his book in an attempt to argue that the existence of the modern State of Israel is based on law and on the sheer presence of the Jewish people. This de jure and de facto support for Israel means, in the view of Koestler, that Israel needs no other justification. Koestler concludes that the Khazar origin of the European Jews “is irrelevant to modern Israel.”

In spite, however, of this theoretical support of Israel, Koestler discloses another purpose for his book. He contends that the traditional orthodox Judaism is presently dying out among Jews everywhere, and that the most significant remaining link among Jews is emotional. The heritage and thought patterns of the European Jews—the Ghetto Jews—are breaking down in Israel and elsewhere. Although a Jew himself, Koestler produced The Thirteenth Tribe to help weaken that emotional link by attempting to detach the Jewish religion from the concept of a chosen people. As such, this book represents Koestler’s effort to enhance Jewish assimilation and undermine the traditional belief of Jews in their unique religious heritage and mission. Koestler’s motives aside, however, it is important to note in conclusion that speculation is not proof, and that far too much of this volume is speculation to merit serious consideration of Koestler’s central thesis.