Moses Mendelssohn was a hugely influential thinker in 18th-century Germany. An unusually gifted intellect, he became the primary spokesperson for the emancipation of Jews in the 18th century, and his cause was championed by many non-Jewish liberals of the era.
Heralded as the founder of the Reform movement even though Mendelssohn himself maintained an observant lifestyle, his activity spawned a wholesale abandonment of traditional Judaism.
Within a century of his death, his strategy of acculturation to the modern era was widely accepted by most Jewish thinkers in western Europe, but not a single one of Mendelssohn’s descendants remained Jewish.