This was a fascinating read. I had not been aware until then of the Khazar empire, nor that a portion of its ruling elite converted to Judaism. Subsequent scholarship has invalidated Koestler's wider claim that the bulk of Ashkenazi (central European Jewry) are of Khazar descent. Yet aside from the truth of this issue, I was disturbed when I finished the book by what Koestler seemed to feel was the implication of his theory, namely, that the mass murder inflicted by the Nazis in the holocaust was a case of mistaken identity, since many of the victims, on Koestler's understanding, were not "really" Jews. In that sense, this book can be seen as one more of the many attempts after 1945 to understand the incomprehensible. ( )

Arthur Koestler was Hungarian by birth, and floated about Europe, settling in England after WWII. His premise, that the bulk of European Jewry, the Ashkenazim, are genetically the descendants of the Turkic tribe, the Khazars, who are recorded as having been converted to Judaism in the 800's AD, was very controversial in its day. Modern Genetics may prove the point, one way or the other.
His theory is that after their conversion, and the break-up of their formal state, the Khazars transferred themselves from a tribal grouping to a section of the Jewish diaspora, and moved further to the West, becoming the bulk of the European Jewish community, as they appeared in much larger numbers than the descendants of the Sephardim, who seem to have been confined to the Mediterranean basin. As the Sephardim are much lower in class in the modern state of Israel, where the European Jews seem to be in control, the Israelis don't like this book very much. I think that it is interesting, especially if true. ( )

History of the ancient Khazar Empire which converted to Judaism

This book traces the history of the ancient Khazar Empire, a major but almost forgotten power in Eastern Europe, which in A.D. 740 converted to Judaism. I think I read this 30 years back but it makes an interesting read especially in light of claims made by Jewry to "going back to the land of their ancestors". If I remember correctly Koestler does some figure work and "proves" that the Eastern European Jewish population could never have reached the number that was present before the Shoah unless there was an influx of other blood into the Jewish race. ( )