The chapter ponders the massive international impact of Renan’s views on Semitic monotheism. This impact, spread across linguistic, religious, and political borders, enduringly echoed the idea of Semitic monotheism. At the same time, it triggered a series of polemical responses that questioned the very legitimacy of the idea. The chapter also reviews new developments among German historians of religion in the last decades of the nineteenth century on the approach of biblical monotheism. In particular, we focus on another major scholarly affair, which took place at turn of the century, around a scholarly school that sought to discredit the idea of the Israelite origins of monotheism. These developments must be understood in the context of the growing racial anti-Semitism. The significant role of Jewish scholars in both affairs, in which the status of ancient Israelite monotheism was questioned, will also be surveyed.