Khazar hypothesis of Ashkenazi ancestry

A largely abandoned historical hypothesis postulated that Ashkenazi Jews were primarily, or to a large extent, descended from converts to Judaism among the Khazars, a multi-ethnic conglomerate of mostly Turkic peoples who formed a semi-nomadic khanate in and around the northern and central Caucasus and the Pontic–Caspian steppe in the late 6th century CE. It is still sometimes used in antisemitic conspiracy theories and in various anti-Zionist approaches. The hypothesis draws on medieval sources such as the Khazar Correspondence, according to which at some point in the 8th–9th centuries, a small number of Khazars were said by Judah Halevi and Abraham ibn Daud to have converted to Rabbinic Judaism.

Source: Wikipedia — Khazar hypothesis of Ashkenazi ancestry (CC BY-SA 4.0)