On the Ninth of Av Jews by tradition remember five major events (although they are not the only events remembered): God punishing Israel with wandering in the desert, the destruction of the First Temple by Nebuchadnezzar, the destruction of the Second Temple by the Romans in AD 70, the crushing of the Bar Kokhba revolt, and the razing of Jerusalem in the aftermath of the revolt in AD 133. The last three of these all contributed to the end of a clearly Jewish strain of Christianity. Jewish Christians emerged specifically from a Jewish context in which Temple service played a central role; its destruction had the inevitable result that Jewish Christian bonds with Gentile Christians became stronger and Jewish Christian bonds with other Jewish groups became weaker. Nonetheless, an explicitly recognized Jewish Christianity survived until the Bar Kokhba revolt. We do not, as far as I am aware, know exactly what made the Simon Bar Kokhba's uprising take fire, although it may have been rumors that the Romans intended to build a temple to Jupiter on the ruins of the Second Temple, but it did and was successful for a while. An independent state of Israel existed for a couple of years. The Romans, of course, would not tolerate such a thing; if it happened here, it could happen anywhere in the Empire, and so they crushed the entire thing mercilessly. As a result, many Jews were killed, much of Jerusalem destroyed, and the Emperor Hadrian exiled all Jews from Jerusalem. The center of Jewish life shifted to Galilee.
We are told by Eusebius that up to this point all the bishops of Jerusalem were "of the circumcision", i.e., Jews actively practicing at least some Jewish practices; after this point, all were Gentiles. It raises some interesting what-might-have-been questions. Without Hadrian's action, would the specifically Jewish character of the Patriarchate of Jerusalem have continued? Would it have had any effect on Christian liturgical practice? By the fourth century Jerusalem's status as one of the Primary Sees was largely honorary, so it might not have had. On the other hand, its negligible character had a great deal to do with the fact that it relatively little to contribute: unlike Rome, Antioch, and Alexandria, it was not a major city, and seems to have had no distinctive liturgical traditions. Would that have been different?
It is perhaps impossible to say, although no doubt there would have been more post-Apostolic Jewish Christians on the calendar of saints, and we are certainly not talking about strongly and obviously Jewish elements, but simply a form of Christianity with more ethnically Jewish aspects. But it does mark a sharp break in the history of the See of Jerusalem. Here are the Jewish bishops of Jerusalem:
The Jewish Patriarchs of Jerusalem
St. James the Just, St. Simeon I, Justus I, Zaccheus, Tobias, Benjamin, John I, St. Matthias I, Philip, Senecus, Justus II, Levi, Ephrem, Joseph I, Judas
Many of these were martyred after a few years of seriving. Three in particular seem to be on the universal calendar of saints.
St. James the Just, of course, is the 'brother of our Lord' mentioned in Galatians, I Corinthians, and Acts, and to whom the epistle of James is usually attributed. He was active in Temple worship, and he was the architect of the compromise position between Gentile Christians and Jewish Christians at what we traditionally call the Council of Jerusalem described in Acts 15. He was was stoned to death by a faction of Jews. His feast day is May 3 on the Roman calendar.
St. Simeon his successor according to tradition was a continuator of this moderation, having been elected in opposition to a movement in Jewish Christianity in favor of more strongly Jewish practice. The Second Temple was destroyed in his day, scattering Jewish Christians; that they survived at all seems to have been due to St. Simeon's work. He is traditionally identified as being the son of Cleophas and thus Simeon the brother of the Lord (Mt 13:55, Mk 6:3); he is sometimes also identified with the Simeon Niger of Acts 13:1. He was crucified by the Romans. His feast day is February 18 in the Roman calendar.
St. Matthias I seems to have been the bishop of Jerusalem during the Kitos War, a major Jewish uprising, which began with Jewish revolts in Cyrenaica in modern-day Libya and spread from there throughout the empire. his feast day is January 30 in the Roman calendar.
Judas of Jerusalem is said to have been the great grandson of Jude the brother of the Lord, and he was the bishop up to the Bar Kochba revolt; he seems to have survived it by at least a decade, although his Gentile successor, Marcus, seems to have been appointed toward the end of the revolt. Given how thoroughly Jerusalem was destroyed, it may have been viewed at the time as the end of the line for the line of bishops of Jerusalem, and Marcus may have been seen more as the bishop of Hadrian's new Aelia Capitolina at the time. On the other hand, given the tumult of the time and the fact that episcopal succession was not completely regularized by then, it may well be that many of the bishops on the list had overlapping episcopal tenures, and this was just one. Regardless, I find it interesting that at least three names on the list are explicitly associated in tradition with the family of Jesus; it perhaps tells us something about how the Jewish Christian movement survived as long as it did.
All of this also raises some interesting questions for modern times. We are living in a period where several longstanding Christian traditions are in a very precarious position in the Middle East. It is a serious possibility that in a few decades Syrian or Chaldean Christianity, for instance, will exist only in exile, and a serious further possibility that if it does it will continue to exist only for a couple of centuries more. Now, both strains are actually quite hardy, so they may survive despite the gloomy outlook. But between active persecution and the ravage of wars made worse by the meddling of Western powers, many Christian groups in the Middle East have been caught between a rock and a hard place for quite some time, with the rock getting rockier and the hard place getting harder. The danger of loss of major traditions is not something confined to the early days of the Church.