Not many decades after the emancipation of the Jews in Western Europe, studies began to appear investigating the causes of anti-Semitism. This study is part of that body of work. However, it differs significantly from recent efforts in that it is situated within Western European history as opposed to Jewish history. This means that it will not be reliant upon Jewish sources. Furthermore, it does not look at anti-Semitism from the viewpoint of liberalism---which declared the illegitimacy of such sentiments---nor is it informed, as is so often the case, by the shadow cast by the Holocaust.It throws into sharp relief a continuum---the rejection of the Jew as Jew---historically achieved through marginalization and reconfigured as a series of stipulated reforms by the Enlightenment thinkers meant to culminate in assimilation. It is the rupture of this continuum---the emancipation of the Jews, the vast majority of whom did not conform to these stipulations---which created the conditions that eventually led to the Holocaust.After summarizing the centuries-long era of Toleration, I address in great detail Enlightenment discourse as it pertained to the Jews. Whereas the Church steadfastly offered only conversion in order to gain acceptance into the general society, the Enlightenment thinkers arrived at a new paradigm, based on Enlightenment ideals. However, it will be shown that their strategy had exactly the same impulse as that of Christianity: to erase all distinctiveness of the Jew. The discussion of this discourse forms the backbone of my study and, in the process, reconfigures the very definition of anti-Semitism.This study maintains that the non-Jewish context was a uniform one, modified only by national and local issues, an assertion many historians have recoiled from. As a first step in confirming uniformity, I have analyzed the response to the failure of emancipated Jews to assimilate in the prescribed ways in Hungary, and then inquired into the same phenomenon in Britain. The similarity of the responses outweighs the differences, demonstrating that the Jewish effort to reform, and thereby to assimilate into the host society was equally unsuccessful in both countries. Christian Europe responded uniformly to the presence of unreformed Jews in its midst.