Christian anti-Jewish polemics have a long and rich history, stretching all the way back to the early stages of the new faith community. Anti-Jewish treatises dot the history of Christian literature from the third century onward. By contrast, Jews seem to have been much less concerned with combatting Christianity. It has been widely noted that the earliest Jewish compositions devoted to anti-Christian polemics stem from the twelfth century. While the twelfth-century provenance of the earliest Jewish anti-Christian tracts has long been recognized, little attention has been focused on the significance of this dating. The fact that sometime toward the end of the twelfth century, perhaps in the 1160s or 1170s, two anti-Christian works, the forerunners of a substantial body of Jewish anti-Christian polemical-apologetic works, were composed almost simultaneously begs interpetation. What changes gave rise to a new Jewish sensitivity, to a need to present Jewish readers with formulation and rebuttal of Christian claims? The answer clearly lies in the enhanced agressiveness of western Christendom toward the Jews, as well as other non-Christians, a development that has been recognized and discussed extensively in modern scholarly literature. In the face of an increasingly aggressive Christendom, Jewish intellectual and spiritual leadership had to reassure the Jewish flock of the rectitude of the Jewish vision and the nullity of the Christian faith. This is precisely what the first two anti-Christian treatises, the Milhamot ha-Shem of Jacob ben Reuven and the Sefer ha-Berit of Joseph Kimhi, undertook to achieve. Given the pioneering nature of these works, it is striking that insufficient scholarly attention has been accorded to these two efforts. They surely have much to tell both of perceived Christian thrusts and of meaningful Jewish rebuttal of these challenges.