Emperor Joseph II issues the Edict of Tolerance, which ensures the rights and duties of Jewish subjects of the Austro-Hungarian empire. Equal civil rights for Jews has been vociferously opposed by most popes, including those who have otherwise eased various restrictions on Jews. This is because treating Jews as civil and political equals implies that Judaism is the equal of Catholic Christianity.
This, however, would contradict the traditional Christian doctrine that Christianity superseded Judaism and, therefore, that Judaism is no longer an entirely valid religion. It may have been valid at one time, but today Jews are obliged to convert to Christianity.