Arthur Koestler - The Thirteenth Tribe (1976) - AZINAS

The Thirteenth Tribe (1976) is a book by Arthur Koestler,
which advances the thesis that Ashkenazi Jews
are not descended from the historical Israelites of antiquity,
but from Khazars, a Turkic people.
Koestler's hypothesis is that the Khazars
(who converted to Judaism in the 8th century)
migrated westwards into Eastern Europe in the
12th and 13th centuries when the Khazar Empire was collapsing.

Koestler used previous works by Abraham Poliak, Raphael Patai
and Douglas Morton Dunlop as sources. His stated intent
was to make antisemitism disappear by disproving its racial basis.

Popular reviews of the book were mixed, academic critiques of its research
were generally negative, and Koestler biographers
David Cesarani and Michael Scammell panned it.