It's amazing how YouTube, TikTok, and independent media, have brought Arthur Koestler's book The Thirteenth Tribe back into the discussion.

Here are two books, published in Israel, most folks don't know about that support or expound on Koestler's hypothesis:
"THE INVENTION OF THE JEWISH PEOPLE" by Shlomo Sand. [a top seller in Israel at the time but controversial as expected]

Then there's "KHAZARIA: HISTORY OF A JEWISH KINGDOM IN EUROPE", by Abraham Polak, an Israeli scholar & historian.
When first published in 1943, it got rave reviews & won literary prizes, with the author being hailed all over the place. Then, some Zionists started changing their minds about the book and it kinda disappeared.

Strange thing is, even before Arthur Koestler's book, the idea that European Jews were converts was widely accepted both by Jewish scholars and others. It was only with the rise of Zionism and the creation of the state of Israel that the idea became controversial. Some have stated that the Khazar theory is why many of the original Zionists changed their last names to a more Hebrew sounding one, for example, Benjamin Netanyahu was Benjamin Mileikowski, etc etc.

Abraham Polak's book is fire! lol