The Theory That Ashkenazi Jews Are Descended from Khazars Is Junk Science

At some point in the 19th century, a number of scholars tried to trace the lineage of East European Jewry not to German Jews who settled there in the late medieval period but to the survivors of the Khazar empire, which ruled over a large area in what is now eastern Ukraine and southwest Russia in the 8th through 10th centuries CE. This hypothesis, popularized by the Hungarian-British writer Arthur Koestler in the 1970s, claims that the Turkic-speaking Khazars converted to Judaism en masse and, after their empire was destroyed, settled throughout Poland, Ukraine, and Belarus, where their descendants came to constitute the bulk of the Jewish population. From this it allegedly follows that most modern Ashkenazim are unrelated to biblical Israelites, and that the historical Jewish connection to the land of Israel is attenuated if not false. Long discredited, the theory has recently been revived by a handful of academics. But the evidence against it is greater than ever, as the linguist and onomastician Alexander Beider explains: