Ernest Renan

Joseph Ernest Renan (27 February 1823 – 2 October 1892) was a French Orientalist and Semitic scholar, expert of Semitic languages and civilizations, historian of religion, philologist, philosopher, biblical scholar and critic. He wrote influential and pioneering historical works on the origins of early Christianity, and espoused popular political theories especially concerning nationalism and national identity. Renan is credited as being among the first scholars to advance the Khazar theory, which helds that Ashkenazi Jews were descendants of the Khazars, Turkic peoples who had adopted Jewish religion and migrated to Western Europe following the collapse of their khanate.

Source: Ernest Renan on Wikipedia