My source for this astounding conclusion is Arthur Koestler's book, The Thirteenth Tribe . Koestler explains that Eastern Europe's Jewish population, largely decimated by the Nazi onslaught during the World War II, were descended from a a tribe known as the Khazars. They were converted to Judaism by their king as a way of balancing their position between the Christian Byzantine Empire on the east and the Muslims on their western and southern borders. When their empire collapsed they immigrated to and settled in Hungary, Poland and Germany, bringing their Jewish faith with them.
This means that the European Jews came from the Caucasus region (southern Russia, Georgia, Azerbaijan and Turkey). Genetically, they are more closely related to the Hun, Uigar and Magyar tribes than to the seed of Abraham, Isaac and Jacob. These folks are known today as Ashkenazic Jews.
The site Judaism 101 seems to ignore this history, preferring to go no deeper than the fact that there were Jews in France, Germany, and Eastern Europe. That site says,
"Ashkenazic Jews are the Jews of France, Germany, and Eastern Europe and their descendants . . . The word "Ashkenazic" is derived from the Hebrew word for Germany. The word "Sephardic" is derived from the Hebrew word for Spain. The word "Mizrachi" is derived from the Hebrew word for Eastern."In later Blogs I'll explore further the views on race promoted in the years leading up to Nazism.