Even after the Fourth Crusade, the Council of Florence almost reestablished full communion between East and West. What went wrong then? Do you know any interesting details and personalities of that Council?
The Council of Florence was largely a missed opportunity. Most of the Orthodox participants at the Council were not there out of a burning desire for Christian unity, but because their empire was about to fall to the Muslims. The Byzantine Emperor hoped that by establishing reunion with the Catholic Church that the western nations would send military aid.
Thus, the reunion was one of political expedience. Because of this, the Orthodox representatives readily agreed to everything proposed by the Latin representatives. There was no real theological discussion, and no issues were resolved. Nor could there be, for most of the Latin representatives were schooled in scholastic theology, and addressed the Council in Latin, using scholastic terminology that the Orthodox were completely unfamiliar with. According to the accounts that I have read, the Orthodox delegates sat there in bewildered silence, completely unable to comprehend what the Latins were talking about.
The Council itself was really doomed from the very start. As soon as the Orthodox delegates arrived, they were greeted with a demand by Pope Eugene IV: the Patriarch of Constantinople had to get down on his knees and kiss the feet of the pope. This outraged the Orthodox Patriarch, who refused to comply. After a tense standoff Pope Eugene eventually relented, but from that point on things were sour.
Most of the Orthodox delegates wanted to just get the reunion over with as quickly as possible, so that they could secure help for their people. However, one Orthodox Bishop – Mark of Ephesus, wanted a real theological dialogue to take place. He believed that there were serious theological controversies that had to be discussed, and he was appalled that his fellow Orthodox bishops put political expedience over issues of faith. After the Council was over, and reunion was officially proclaimed, the Orthodox bishops returned home. Upon his return Mark of Ephesus wrote vehemently against the Council, calling it a “false union,” and he stirred up public opinion against it. However, the Orthodox leadership remained in full communion with Rome right up until Constantinople fell (the promised military aid from the West never materialized). When the Muslims took over the city, they appointed Orthodox bishops who were opposed to the union, and it was officially dissolved.
In my humble opinion, one of the major reasons that the union failed was that it was a union from the top down. The common folk were not supportive of it, and in many cases bitterly opposed it. For a genuine reconciliation to occur, it must be from the bottom up. When Orthodox and Catholic Christians come to recognize one another as brothers and sisters in Christ, they will be willing to work through the issues and reunite as one Church.