Now we get to some especially tangled and complicated aftermaths. As usual, I am artificially only considering a hundred years, for practical convenience, but really we are still dealing with the aftermath of both of these ecumenical councils.
Council of Ephesus (431)
The appointment of Nestorius as Patriarch of Constantinople in 428, and subsequent controversy over his Christological claims, led to an intense stand-off between the sees of Alexandria and of Constantinople, the two major rivals for the foremost Eastern see. Theodosius II and Nestorius called the Council of Ephesus in order to put the Patriarch of Alexandria, Cyril, in his place, but Cyril completely outmaneuvered them both, taking over the council and using his connections to stir up protests that made it impossible for Theodosius to continue to support Nestorius.
First Quarter (431-456)
The council occurred at a time of special strain between the Roman and the Persian empires; the Persian Empire, which was officially Zoroastrian, was highly suspicious of the Church of the East, which had been increasingly persecuted as having foreign allegiances. In 424, under intense pressure from the Sasanid government, the Persian hierarchy had formally and explicitly declared itself independent of the Byzantine episcopal hierarchy, . The result was that the Persians stopped sending even token representatives to major councils in the Roman empire, and, unlike previous major councils, the Council of Ephesus was not confirmed by a corresponding council of Persian bishops. The Zoroastrian government also actively gave support to Nestorians who fled to Persia, and exempted them from most of the increasing persecutions of Christian bishops. However, at this time, the Church of the East was not officially or formally opposed to the Church in the Byzantine Empire on any doctrinal point.
St. Cyril's victory at Ephesus made him in any ways the most important and influential bishop in the Roman Empire. His death in 444, however, led to a series of disputes about how to interpret his legacy. Disputes over Eutychianism in particular, which held that divinity and humanity were blended in Christ into a new nature, led to duelling councils: the Second Council of Ephesus in 449, which resolved in favor of a form of Eutychianism, and the Council of Chalcedon in 451, which resolved against. Alexandria supported the Second Council of Ephesus, which it had largely led, but the Council of Chalcedon was supported by Constantinople and Rome. The dispute between the Chalcedonians and the Alexandrians would become increasingly intractable.
Second Quarter (456-481)
Babowai became Catholicos of the Church of the East in 457, and his tenure would be rocky from the start; he was a convert from Zoroastrianism, so the Sassanid government, regarding him as an apostate, was already inclined to hostility toward him. He was also an active voice in the Church of the East for maintaining ties with the Church in the Byzantine empire. He was, as many converts are, not inclined to be intimidated by the members of his former religion, and managed to continue for some time, but his downfall would occur due to his repeated opposition to other bishops in the Church of the East, the most important of whom was Barsauma of Nisibis. The primary source of the opposition was not doctrinal, originally, but a matter of church discipline: Babowai and his supporters wanted to uphold the tradition of celibacy for bishops, whereas Barsauma and his supporters saw episcopal marriage as a way of differentiating themselves from the Roman bishops. Thus for most of Babowai's tenure as Catholicos, the Church of the East was practically split between those who supported Babowai and those who supported Barsauma, a split that would grow ever worse as time went on. Babowai was at some point imprisoned and spent about seven years under terrible conditions, including sporadic torture, until he was released somewhere around the year 480.
Third Quarter (481-506)
While Catholicos Babowai had been released from prison, Barsauma had managed at some point to intercept messages between Babowai and bishops in the Roman Empire, in which Babowai asked them to use their influence with the Roman emperor to see if he could do anything to restrain the Sassanid government's persecution of Christian bishops. Barsauma showed the letter to the Emperor Perosz I at some point. The result was that Babowai was executed as a traitor the Persian Empire in 484. Supporters of Babowai still had some support, and when a Catholicos was eventually chosen, they managed to get Acacius of Seleucia-Ctesiphon selected in 485. Catholicos Acacius was a moderate; he wanted to maintain the independence of the Church of the East but viewed anti-Romans as extremists. Nonetheless, Babowai's death and Barsauma's relatively good relations with the Persian emperor made Barsauma the most powerful bishop in the Empire, and he was able, partly by influence and partly by threats, to prevent Acacius from having much of an effect. A synod was held at Beth Edrai in 485 and the even more important Synod of Seleucia-Ctesiphon in 486 officially defined the Persian hierarchy's devotion to the theology of Theodore of Mopsuestia, which they saw the theology of the Council of Ephesus as opposing.
In 489, the Roman emperor Zeno shut down the famous catechetical school at Edessa because of what was seen as its support for Nestorianism; in response, Barsauma re-opened the school at Nisibis, which had been its original home, which resulted in further Nestorian migration to Persia. However, in the wake of increasing Roman enforcement of Chalcedon, Monophysitism was also spreading in Sassanid territory, with the result that Barsauma found himself in a constant struggle to maintain his influence, and he was forced to make some concessions to the moderates in the face of this new set of opponents. Barsauma died in 491, according to some stories stabbed to death by the Monophysites of the monastery of Tur Abdin.
Fourth Quarter (506-531)
In the Roman Empire, the fourth quarter sees the firmer consolidation of the anti-Nestorian position of the Council of Ephesus. In Sassanid territory, matters were considerably more complex. Beyond the Church of the East's firm adherence to Theodore of Mopsuestia and the rejection of a policy of episcopal celibacy, the exact nature of the opposition between the Church of the East and the hierarchy of the Roman Empire would continue to be fluid and confused for a very long time, only receiving clarification in the seventh century.
Council of Chalcedon (451)
First Quarter (451-476)
The Council of Chalcedon ruled against Eutychianism. It also deposed Patriarch Dioscorus of Alexandria, who was the major supporter of the Second Council of Ephesus that the Council of Chalcedon opposed, although it did so for refusing to obey a summons under canon law. Dioscorus claimed he had been ill and physically unable to attend (this is generally thought to have been an excuse, but this is not wholly certain), but he was exiled to Gangra, where he would die in 454. St. Proterius was appointed in his place in 451; Alexandria itself was unusually quiet over the matter at first, although there was evidence that Dioscorus continued to be supported in secret by a large portion of the population, although problems soon began to increase. Proterius's tenure would see an ever-increasing set of problems developing between the church in Alexandria, officially in support of Chalcedon, and the Coptic churches to the south in Ethiopia. Proterius would be murdered in 457, although we have conflicting accounts of how it happened. The bishops elected Timothy II Ailuros as patriarch; as he was firmly opposed to Chalcedon, Emperor Leo I exiled him and appointed Timothy III Salophokailos. In about 469, Peter Fuller, having apparently engaged in a rumor campaign against Patriarch Martyrius, accusing him of being a Nestorian in terms that led to his deposition, became Patriarch of Antioch and began campaigning against Chalcedon. Martyrius unsurprisingly went to Constantinople; supported by the Emperor and the Patriarch of Constantinople, he was restored, but Peter Fuller, who seems to have been truly a master of politics, had cultivated so many allies in Antioch that Martyrius was soon forced to leave again. Emperor Leo exiled Peter Fuller, who fled; a pro-Chalcedonian bishop, Julian I, was then made Patriarch of Antioch.
In January of 474, the general Basiliscus staged a coup against Emperor Zeno, and Zeno was forced to flee. Basiliscus was vehemently anti-Chalcedonian. In April, he issued an encyclical officially recognizing the first three ecumenical councils and rejecting Chalcedon.the Third Council of Ephesus in 475, and bishops like Timothy Ailuros and Peter Fuller who supported Basiliscus's encyclical were restored to their sees. Both anti-Chalcedonian patriarchs seized their opportunity and began widely ordaining priests and bishops, expanding their sphere of influence and creating the basis for what would eventually be the Oriental Orthodox hierarchy.
Second Quarter (476-501)
Basiliscus, however, being a very poor politician, did not survive long, and fled on Zeno's return to Constantinople in August of 476. Zeno annulled Basiliscus's anti-Chalcedonian policies later that year, and Peter Fuller fled Antioch when the emperor's men came for him. Timothy Ailuros died in 477, before he could be removed; the bishops elected Peter Mongus to replace him, but he was not able to have possession long, because Zeno restored Timothy Salophokailos, who would remain Patriarch of Alexandria until his death in 481.
However, new complications were brewing, as Zeno faced an empire that was in religious and political chaos. Odoacer seized control of the governing structures of the West, Zeno faced multiple revolts in the East, the major sees were all officially Chalcedonian, the populace of Constantinople was vehemently pro-Chalcedonian, anti-Chalcedonianisms of various kinds were extremely popular in Alexandria and in Antioch. Thus the emperor attempted to find a way to prevent civil war, and his solution was the Henotikon, promulgated in 482, an attempt to find a compromise position between Constantinople and Alexandria that would not force him to expend endless resources in keeping the East together. Acacius, the Patriarch of Constantinople, who had been consulted in its formulation, supported the Henotikon. When Peter Fuller promised to support it, he was restored to the see in Antioch. After Timothy Sophokailos's death, John Talaia had been made Patriarch of Alexandria; he refused to accept the compromise, so when Peter Mongus promised to support it, he was restored to the see and John was exiled.
The East finally had a unified religious position on the matter, but Zeno had perhaps forgotten that the see of Rome held the Tome of Leo, promulgated by Chalcedon, to be non-negotiable. John Talaia fled to Rome, and was welcomed by the Popes, who was welcomed by Pope St. Simplicius. Simplicius's successor, St. Felix III. Pope Felix began an active and unyielding campaign against the Henotikon, eventually excommunicating Peter Fuller, Acacius, and Peter Mongus in 484; this is the beginning of the Acacian Schism between East and West. Acacius died in 489 and was succeeded by Patriarch Fravitas, who tried to reconcile with Rome without dropping the Henotikon; he failed, in part because he seems to have said different things to both sides. When his duplicity was eventually discovered by Pope Felix, it simply made the schism worse. Fravitas's successor, Euphemius, broke communion with Peter Mongus and re-affirmed Chalcedon, but he also refused to condemn his Henotikon-supporting predecessors, and neither Felix nor his successor St. Gelasius I would yield on the point, perhaps because they suspected a ruse like that of Fravitas.
Euphemius's strategy was more successful with Gelasius's successor, Pope Anastasius II; as long as the other sees affirmed Chalcedon and the Tome of Leo, Anastasius was willing to be flexible about other things. This outraged the Western bishops, but Anastasius's policy was never really implemented because he died suddenly and unexpectedly in 498; his death was taken by pro-Chalcedonian bishops as a sign of divine judgment. The succession was then highly disputed; two different candidates were elected by different groups, St. Symmachus and Laurentius; King Theoderic, the Ostrogoth king, ruled that the one who was elected first would be recognized as pope, although he may have chosen that criterion specifically because he did not want Laurentius, a vehement pro-Byzantine, to be pope. The Laurentians accused Symmachus of buying the office and therefore refused to recognize him as pope; thus began the Laurentian Schism.
Third Quarter (501-526)
The Western bishops were tied up throughout 501 and 502 trying to resolve the Laurentian Schism. Once it was out of the way, however, there still remained all the problems of the Acacian Schism that had caused it. St. Hormisdas became pope in 514. In the meantime, the East was in an uproar; despite official acceptance of the Henotikon by the eastern sees, in fact large portions of the population rejected it. In 513, the general Vitalian, commander of the Imperial calvary, led a revolt against the emperor, at that time Anastasius I. St. Flavian II had been a supporter of the Henotikon, and thus had been appointed by Emperor Anastasius as Patriarch of Antioch; however, somewhat unexpectedly, it turned out that he also accepted Chalcedon. This led the anti-Chalcedonians to accuse him of Nestorianism, and his major episcopal opponent, Philoxenus of Hierapolis, eventually worked up a mob to try to force him to repudiate the council; Chalcedonians flocked to support Flavian, however, and a brutal mob battle erupted between the two groups, with the Chalcedonians routing the Monophysites. Because of this he was deposed and exiled in 512 (where he would die in 518), which had led to an immense unrest throughout the region, which Vitalian had had the initiative to seize. Vitalian was eventually defeated, but the revolt seems to have convinced Anastasius that something needed to be done. The emperor invited the pope to a synod to discuss the matter; a negotiation began over the terms, but Anastasius still insisted on the Euphemian policy. Anastasius was succeeded by Justin I in 518; Emperor Justin, being pro-Chalcedonian and advised by his even more pro-Chalcedonian nephew, Justinian, almost immediately accepted all of the terms Pope Hormisdas had laid down in the negotiations, and the Acacian Schism was officially ended between Rome and Constantinople in 519.
Antioch and Alexandria were another matter. Flavian II had been succeeded by Severus, an immensely competent anti-Chalcedonian, who affirmed the Henotikon but rejected Chalcedon. At the Synod of Tyre in 514, Severus had managed to have this confirmed. When Justin took the throne, he demanded that Severus reject the Henotikon and accept Chalcedon, but Severus refused; warned by Justin's wife, Theodora that Justin had ordered him to be arrested and have his tongue cut out, Severus fled. He was welcomed in Alexandria by the Patriarch, Timothy III (Timothy Sophokailos was not recognized as having been a legitimate patriarch).
Fourth Quarter (526-551)
Justinian succeeded Justin in 527 and, although a Chalcedonian himself, made an effort to deal with the increasingly disruptive problem of the anti-Chalcedonians by opening discussions. To some extent this backfired, as in 535 Severus was able to convince the new Patriarch of Constantinople, Anthimus, that the anti-Chalcedonian position was the right one. In 536, however, Pope St. Agapetus I of Rome arrived in the city on an embassy from Theoderic; while there, he convinced Justinian to reaffirm support for Chalcedon, depose Anthimus, and consecrated Anthimus's successor, St. Menas. Menas held a synod that excommunicated Severus, Timothy, and their supporters. In retaliation, the supporters of Severus and Timothy began setting up parallel institutions and offices rather than (as previously had been the usual practice) fighting over the same institutions and offices. This momentous change would radically shift the nature of schism itself, by creating the first attempt at a clean non-temporary cut between churches. Justinian attempted to shut down this attempt, but the supporters of Severus and Timothy were often too well-entrenched for him to do so effectively. On the other side, though, it meant that the Oriental Orthodox, as they later came to be called, were no longer trying to take control of Orthodox sees, and within the Orthodox sees, opposition to Monophysitism was able to be consolidated.
In 543, Justinian tried again, in particular focusing on the common Monophysite complaint that Chalcedon had been a reversion to Nestorianism. At least part of the idea seems to have been suggested by an Origenist monk named Theodorus Ascidas, who was hoping that helping Justinian deal with the Monophysite problem might distract him from his rumored desire to crack down on Origenists. The idea was to condemn three sets of writings: the works of Theodore of Mopsuestia, some of the anti-Cyrilline works of Theodoret of Cyr, and a letter of Ibas of Edessa. Chalcedon had not condemned Theodore (probably deliberately), despite his influence on Nestorius; it had restored Theodoret to his see; and it had not seen fit to criticize the letter of Ibas despite being aware of it. Monophysites criticized it on all three points, so Justinian likely thought that remedying these oversights would make it easier to negotiate with the followers of Severus and Timothy. He issued an edict against the three sets of writings, which eventually came to be known as the Three Chapters, and began pushing bishops to sign it. St. Menas refused at first, worried that it would be seen as a repudiation of Chalcedon, but was eventually convinced to sign on the condition that his signature could be retracted if Rome disapproved. The other Eastern Orthodox patriarchs were also reluctant but eventually yielded. The Latin bishops, however, suspicious by this point of any attempt whatsoever to compromise on Chalcedon, resisted much more vigorously. For them, it was not a matter of content -- most of them could not read Greek, and full information of the situation was anyway not always available -- but about upholding the Tome of Leo and repudiating anything that might seem disloyal to that goal. When Pope Vigilius -- who had been suspected originally of being a Monophysite and seems to have wanted to avoid any Monophysite associations -- also resisted, he was summoned to Constantinople by Justinian to discuss the matter. Vigilius arrived in Constantinople in 547, with every bishop he had spoken to obviously angry at the condemnation of the Three Chapters, the route to Constantinople lying through territory that was most opposed to Justinian's move.
Vigilius seems to have arrived determined to excommunicate St. Menas for signing, but was stopped when he was provided translations of some passages for Theodore of Mopsuestia that seemed strongly to suggest something like a Nestorian position. So he stopped to study the matter, and changed his mind, issuing in 548 the Judicatum condemning the Three Chapters. The uproar this caused among Latin bishops was so extensive that Vigilius then withdrew the Judicatum. Then Vigilius and Justinian came to an agreement that they should both wait until a general council could be called; then Justinian broke the agreement by issuing a further condemnation of the Three Chapters. Vigilius and Justinian came to an agreement again to call a general council, but this time Vigilius is the one who changed his mind. Nonetheless, Justinian was determined, and a general council would in fact be called, the Second Council of Constantinople, which would actually take place just outside our artificial bounds for the aftermath of the Council of Chalcedon, in 553.