Anti-Judaism is the "total or partial opposition to Judaism—and to Jews as adherents of it—by persons who accept a competing system of beliefs and practices and consider certain genuine Judaic beliefs and practices as inferior."[1]

Anti-Judaism, as a rejection of a particular way of thinking about God, is distinct from antisemitism, which is more akin to a form of racism. Scholars who see a less clear line between theology and racism have since coined the term religious antisemitism.

Nevertheless, the concept of Judaism has been challenged over the past two thousand years by scholars of both Christendom and Islam.

Pre-Christian Roman Empire

In Ancient Rome, religion was an integral part of the civil government (see Religion in ancient Rome). Beginning with the Roman Senate's declaration of the divinity of Julius Caesar on 1 January 42 BC, some Emperors were proclaimed gods on Earth, and demanded to be worshiped accordingly[2] throughout the Roman Empire. This created religious difficulties for monotheistic Jews and worshipers of Mithras, Sabazius and Early Christians.[3] Jews were prohibited by their biblical commandments from worshiping any other god than that of the Torah (see Shema, God in Judaism, Idolatry in Judaism).

The Crisis under Caligula (37-41) has been proposed as the "first open break between Rome and the Jews", even though problems were already evident during the Census of Quirinius in 6 and under Sejanus (before 31).[a]

After the Jewish-Roman wars (66-135), Hadrian changed the name of Iudaea province to Syria Palaestina and Jerusalem to Aelia Capitolina in an attempt to erase the historical ties of the Jewish people to the region.[b] In addition, after 70, Jews and Jewish Proselytes were only allowed to practice their religion if they paid the Jewish tax, and after 135 were barred from Jerusalem except for the day of Tisha B'Av.

Flavius Clemens was put to death for "living a Jewish life" or "drifting into Jewish ways" in the year 95 CE, which may well have been related to the administration of the Jewish tax under Domitian.[c]

The Roman Empire adopted Christianity as its state religion with the Edict of Thessalonica on 27 February 380, see State church of the Roman Empire.