In 614 AD the Byzantine Empire lost its spiritual centre when the Persian Empire under Chosroes II and one of those who chronicled this event in his 'Exomologesis' was a monk named Antiochus (usually called Antiochus of Palestine or Antiochus Strategos) who was an eyewitness to many the events that he describes. The interesting thing about this chronicle - which tells of the woes suffered by the Christians at the hands of the Persians and their allies - is that it includes a fairly substantive mention of the treatment of the Christians of Jerusalem by the jews.
I quote:
'Thereupon the vile Jews, enemies of the truth and haters of Christ, when they perceived that the Christians were given over into the hands of the enemy, rejoiced exceedingly, because they detested the Christians; and they conceived an evil plan in keeping with their vileness about the people. For in the eyes of the Persians their importance was great, because they were the betrayers of the Christians. And in this season then the Jews approached the edge of the reservoir and called out to the children of God, while they were shut up therein, and said to them: 'If ye would escape from death, become Jews and deny Christ; and then ye shall step up from your place and join us. We will ransom you with our money, and ye shall be benefited by us.' But their plot and desire were not fulfilled, their labours proved to be in vain; because the children of Holy Church chose death for Christ's sake rather than to live in godlessness: and they reckoned it better for their flesh to be punished, rather than their souls ruined, so that their portion were not with the Jews. And when the unclean Jews saw the steadfast uprightness of the Christians and their immovable faith, then they were agitated with lively ire, like evil beasts, and thereupon imagined another plot. As of old they bought the Lord from the Jews with silver, so they purchased Christians out of the reservoir; for they gave the Persians silver, and they bought a Christian and slew him like a sheep. The Christians however rejoiced because they were being slain for Christ's sake and shed their blood for His blood, and took on themselves death in return for His death...
When the people were carried into Persia, and the Jews were left in Jerusalem, they began with their own hands to demolish and burn such of the holy churches as were left standing...
How many souls were slain in the reservoir of Mamel! How many perished of hunger and thirst! How many priests and monks were massacred by the sword! How many infants were crushed under foot, or perished by hunger and thirst, or languished through fear and horror of the foe! How many maidens, refusing their abominable outrages, were given over to death by the enemy! How many parents perished on top of their own children! How many of the people were bought up by the Jews and butchered, and became confessors of Christ! How many persons, fathers, mothers, and tender infants, having concealed themselves in fosses and cisterns, perished of darkness and hunger! How many fled into the Church of the Anastasis, into that of Zion and other churches, and were therein massacred and consumed with fire! Who can count the multitude of the corpses of those who were massacred in Jerusalem!' (1)
Now it is not difficult to see that the above is a fairly vicious attack on the jews by a Christian monastic (I am not elaborating on it largely because the text is self-explanatory), but what is important to emphasize is that regardless of the fact that Antiochus' text is invective per se: it is also a chronicle of what happened by someone who may or may not have been there and if he was not there then he would have known eyewitness who had been.
The historicity of the account is also hard to dispute given the fact that the Roman Empire - which then became the Byzantine Empire - had long had an acrimonious relationship with its jewish subjects and Emperors - both Christian and Pagan - had long regarded the jews with suspicion and even outright hostility.
This suggests that one of two possible explanations to us in so far as the jews could have been driven into the arms of the Persians by Imperial persecution or the jews could have been against the Romans and Byzantines throughout the centuries they had been part of the successive empires with the events in Jerusalem just giving voice to that sentiment after having had it passively or actively suppressed due to their material circumstances for quite some time.
The latter seems the more likely of the two explanations - although scholars traditionally plump for the former as it neatly removes any need to investigate whether the jews had any non-material motivations for what they did - as it fits with jewish behaviour in the mid-late Roman Empire (2) as well as jewish behaviour in Spain before, during and after the Islamic conquests (where the jews were active traitors to the Visigothic kingdoms and acted as a pro-Islamic fifth column inside Spain's cities). (3) It is also worth noting that the jews had long had a friendly association with the Parthian/Persian Empires in part because they contained large numbers of jews who we know with some certainly held positions of responsibility and influence. (4)
Indeed, jewish assistance for anti-Roman/Byzantine powers has quite some history: pre-dating even the formation of the Roman Empire and stretching back to the last years of the Roman Republic! (5)
This situational context is important precisely because without it the explanation that the jews were just persecuted into having nothing to lose but to help the Persians seems quite appealing. When you factor in this situational context however: it becomes quite clear that the jews are not interested in anything but either general vengeance against Rome/Byzantium and/or using anti-Roman/Byzantine powers to sweep away their imperial masters so that they can in time forge a new jewish state.
In essence the jews weren't being oppressed by anyone in particular - to be sure they had statutory laws of long-standing against them but they were also afforded significant protection under these same laws - and their betrayal and then murder of Christians at Jerusalem (conducted as if it were a sport no less) then the defiling of its churches goes well beyond the pale of simple 'resentment against persecution' and more into vengeance and the nationalistic thirst for power and dominion.
This ironic especially as jewish historians - such as Samuel Glassman - when recounting the seventh century anti-jewish riots and jewish support for the later Muslim invaders in both Asia Minor and Spain do not mention the catalyst event (jews killing Christians for vengeance/sport in Jerusalem in 614 AD and also working with the Persian Empire against the Byzantines). (6) Instead, they mention the effect (anti-jewish riots in Constantinople/Byzantium as well as the wave of Byzantine legal repression of the jews that followed this) and what they see as the concomitant jewish sympathy for Islam and hatred of Christians due to this 'unjust irrational persecution'.
Glassman and others are misrepresenting the situation quite considerably, because they are citing everything but the founding event and then representing the Byzantine dislike of jews as being ex nihilo so as to fit into their broad narrative that the jews were unjustifiably and irrationally persecuted for things they didn't do as opposed to being rational prosecuted for things they most certainly did (i.e. the anti-jewish riots and legislation were irrational because they had no rational trigger [which we can clearly see that they did]).
We can thus see that Antiochus of Palestine's chronicle of the behaviour of the jews towards the Christians is actually likely to be very accurate with the odd rhetorical flush perhaps and that this murderous and spiteful jewish behaviour was then the cause of a wave of anti-jewish riots and legislation in the Byzantine Empire, which then escalated over centuries with the jews actively helping the armies of Islam leading to the slaughter of jewish communities across Europe at the time of the First Crusade (which occurred - we should remember - at the behest of the Byzantine Emperor).
So, who ultimately caused jewish suffering in these later centuries?
The jews themselves.
References
(1) Frederick Conybeare, 1910, 'Antiochus Srategos: The Capture of Jerusalem in 614 AD', English Historical Review, Vol. 10, pp. 508-509
(2) For example: Eusb. Pamp. Ecc. Hist. 4:2.1-5; Cassius Dio, 68:32.1-3
(3) Eliyahu Ashtor, 1973, 'The Jews of Moslem Spain', Vol. I, 1st Edition, Jewish Publishing Society of America: Philadelphia, pp. 10-16
(4) Leon Poliakov, 2003, [1973], 'The History of Anti-Semitism', Vol. II, 1st Edition, University of Pennsylvania Press: Philadelphia, pp. 12-15
(5) Adrianne Mayor, 2010, 'The Poison King: The Life and Legend of Mithradates, Rome's Deadliest Enemy', 1st Edition, Princeton University Press: Princeton, p. 341
(6) Samuel Glassman, 1980, 'Epic of Survival: Twenty-Five Centuries of Anti-Semitism', 1st Edition, Bloch: New York, p. 64