Why did pagans and the Christian Church dislike Jews

Edward Gibbon (The Decline and Fall of the Roman Empire) says that although Jews believed that it was unlawful for them to pay taxes to an idolatrous master, and in spite of their several uprisings, the attitude of the pagan emperors to their Jewish subjects was one of tolerance. He says, “Since the Jews, who rejected with abhorrence the deities of their sovereign and by their fellow-subjects, enjoyed the free exercise of their unsocial religion, there must have existed some other cause which exposed the disciples of Christ to those severiities from which the Jews were exempt.”

Gibbon goes on to say, “Under the reign of Constantine, the Jews became the subjects of their revolted children [Christians], nor was it long before they experienced the bitterness of domestic tyranny.The civil immunities which had been granted or confirmed by Severus were gradually repealed by the Christian princes; and a rash tumult, excited by the Jews of Palestine, seemed to justify the lucrative modes of oppression which were invented by the bishops and eunuchs of the court of Constantius.”

So Edward Gibbon says that anti-Semitism was uniquely Christian in character and was added to by the corruption of court and Church under the Christian emperors.