That anti-Jewish prejudice features among Latin authors of the early Principate cannot be doubted.
For example, in the Cena Trimalchionis, which is a part of the satirical novel Satyricon, written during Nero's reign, two freedmen- Habinnas and Trimalchio- have a discussion on the slaves they own. The former mentions a particular favorite of his, but adds that his "duo vitia" ("two vices") are that "recutitus est et stertit" ("he is circumcised- i.e. a Jew- and he snores"- Petronius 68.8).
Similarly, in Satire 3, the poet Juvenal, who lived during the reign of the Antonine dynasty at the turn of the second century CE, has a certain Umbricius complain that at Rome, the Jews have taken over the grove of Numa (a symbol of traditional Roman religion).
It has commonly been held that the Jewish Revolt (66-73 CE) marked a turning point in anti-Semitism among Romans. Namely, prior to the Jewish revolt, it has been widely argued that Jews were merely seen as silly rather than sinister or threatening in any way, with, for example, the dietary laws and prohibition against working on the Sabbath sometimes subjected to mockery.
However, I do not find such a view of Roman anti-Semitism tenable. In this context, an incident particularly worthy of consideration is a senatorial decree from 19 CE that ordered practitioners of Egyptian and Jewish rites to either abandon their religion or face expulsion from Italy.
The historian Tacitus (Annals II.85) provides further details:
actum et de sacris Aegyptiis Iudaicisque pellendis factumque patrum consultum ut quattuor milia libertini generis ea superstitione infecta quis idonea aetas in insulam Sardiniam veherentur, coercendis illic latrociniis et, si ob gravitatem caeli interissent, vile damnum; ceteri cederent Italia nisi certam ante diem profanos ritus exuissent.
"And there was a discussion about the expulsion of the Egyptian and Jewish rites, followed by a senatorial decree that 4000 freedmen infected with that superstition and of suitable age should be brought to the island of Sardinia in order to keep a check on the activities of bandits there; and, if any of them perished because of the harshness of the climate, it would be a cheap loss; the rest were to leave Italy unless they abandoned their profane rites before a certain day."
Not much different then from the decrees issued against Jews in the Iberian Peninsula after the completion of the Reconquista in 1492. The contingent of 4000 freedmen sent to Sardinia is also noted by Josephus and described as a unit of Jewish men only, rather than Egyptians.
The decree was brought on the Emperor Tiberius' instigation. Josephus recounts an incident whereby four Jewish rascals had apparently persuaded a noble Roman lady who had converted to Judaism- Fulvia- to provide purple and gold for the Temple in Jerusalem, which they then took for themselves; whereupon Fulvia's husband Saturninus informed Tiberius of the matter.
As for the practitioners of the Egyptian rites, Josephus notes that a noble lady called Paulina (married to another Saturninius) was seduced by a certain Decius, who employed methods of trickery in collaboration with priests of Isis in Rome.
Now, as Heidel convincingly argued in an article published in the American Journal of Philology in 1920, there is a connection between the cases of Fulvia and Paulina. The latter was guilty of "religious prostitution" in Egyptian rites, while the fact that Fulvia was asked to provide purple for the Temple at Jerusalem probably suggested to Tiberius that the Jewish rascals were seeking to make her a "temple prostitute", a practice inconsistent with Jewish rites.
Nonetheless, if we accept these reasons alone as the justification for the senatorial decree, the harshness seems unbecoming of Tiberius' characteristic moderatio at the time, which is evident, for example, in his speech to the Senate in 20 CE, urging the senators not to accept the accusations against Piso - who was accused of murdering the Emperor's adopted son Germanicus, inter alia - as true without proper consideration of the evidence, just because of Tiberius' grief over Germanicus' death (Annals III.12).
In a similar vein, speculating on the possible influence of Aelius Sejanus, the Prefect of the Praetorian Guard who later became Tiberius' "partner in labors" and then consul in 31 CE (only to be executed on charges of treason), is of little help in explaining the nature of the senatus consultum.
Had Sejanus played any part in the Emperor's instigation of the senatorial decree, it would surely have been documented by Tacitus, who portrayed Sejanus as a reincarnation of the villainous Catiline (Annals IV.1) and was eager to note any instances of the man's perceived influence on Tiberius' decision-making.
Instead, it makes sense to begin by noting, as Heidel did, that the decree effectively treats the Egyptian and Jewish rites as identical. The cases of Fulvia and Paulina must therefore have fuelled existing Roman prejudices and suspicions about Egyptian and Jewish religious practices.
The nature of these hostile attitudes can be ascertained from Virgil's Aeneid, an epic poem written in the first century BCE to celebrate the founding of the Roman race by Aeneas, who was the reputed ancestor of Augustus - the predecessor of Tiberius - and the Julian line. The Aeneid's influence cannot be overstated, since it became a school-text for educated Romans, and on graffiti at Pompeii and other sites, it is not uncommon to find single-line excerpts from the epic poem.
In an extended description of the Battle of Actium (31 BCE) as depicted on Aeneas' shield, Virgil depicts the clash as an East vs. West conflict, with Marc Antony and Cleopatra representing the forces of the East that encompass nations like Indians and Arabs, while Augustus leads the armies of Italy. Of particular note are these lines (Aeneid 8.698-700):
omnigenumque deum monstra et latrator Anubis/ contra Neptunum et Venerem contraque Mineruam/ tela tenent.
"All sorts of monstrous gods and the barking Anubis hold their weapons against Neptune, Venus and Minerva."
It is clear that the gods of Egyptian religion (and perhaps Eastern deities more generally) are represented here as sinister forces that are naturally opposed to the gods of traditional Roman religion.
Hence, on the basis of conflation of Egyptian and Jewish rites, it seems reasonable to conclude that Tiberius and the Senate saw the Egyptians and Jews as somehow a malicious threat to Roman religion and morality in society. The link with Juvenal's complaint nearly 100 years later about the Jewish takeover of Numa's grove in Satire 3 could not be more apparent.
The cases of Fulvia and Paulina only vindicated that animosity in the Romans' minds, and so the only appropriate solution for the Emperor and the Senate was to decree that the Jews and Egyptians in Italy should either convert or leave, with particular furor directed at the Jews, something that is illustrated by the forced conscription of 4000 Jewish men to deal with brigands in the harsh climate of Sardinia.
In short, the senatorial decree of 19 CE suggests continuity in Roman anti-Semitism rather than any crucial turning-point in attitudes because of the Jewish Revolt.
Translations of Latin text are the author's own.