In Siege, the emperor Constantine pushes through the Union of the Catholic and Orthodox churches, hoping to receive aid from the West.  However, his push for union only divides his people, inciting the Greek monk Gennadius to do whatever it takes to keep union from occurring.

While the role of Gennadius is somewhat exaggerated in Siege, there can be no doubt that he was a stubborn foe of union.  There can also be no doubt that the struggles over union played a key role in the fall of the city.  Successive emperors pressed hard for union, gambling that the aid it brought would offset the dissension it bred.  But their gamble did not pay off.  Despite the Pope’s call to arms, very little help came from the West.  The Union served only to embitter and divide the people of the empire.

The Union was an attempt to bridge a divide between Rome and Constantinople that had been centuries in the making.  The schism between the Catholic and Orthodox churches had its roots in politics, theology, and culture.  The origins of the break can be traced to 395 AD and the death of Theodosius, the last emperor of a unified Roman Empire.  After Theodosius, Rome split permanently into two empires, one ruled from Rome and the other from Constantinople.  The two quickly grew apart.  Latin remained the dominant language in the West while Greek eventually became the language of the East.  In the West, Rome was overrun by Germanic tribes, who had a huge impact on the development of Christianity there.  As Roman political power faltered, the Church increasingly took over a political role, and the Pope emerged as the most powerful secular ruler in the West.  In the East, the empire continued to thrive.  Constantinople was a powerful, affluent city.  The Patriarch remained a religious figure, more concerned with the purity of doctrine than with the political and logistic troubles that occupied the Pope.

The theological differences that divide the two churches seem arcane enough, but to theologians they were important.  The origin of the split revolves around a portion of the Nicene Creed known as the filioque doctrine (filioque is Latin for “and the son”).  The original creed, agreed upon in 381 AD at the Council of Constantinople, read as follows: “We believe in the Holy Spirit, the Lord, the Life-Giver, Who proceed from the father.  With the Father and the Son, He is worshipped and glorified.”  In 589 AD, the Third Council of Toledo, amended the Nicene Creed to read: “We believe in the Holy Spirit, the Lord, the Life-Giver, Who proceeds from the father and the Son.  With the Father and the Son, He is worshipped and glorified.”  This new version of the Creed eventually spread to all the western churches.  It was rejected in the East, most notably by Patriarch Photius, who in 867 AD excommunicated the Pope for supporting the filioque doctrine.  Nevertheless, the doctrine continued to gain support in the West, and in 1014 AD, it was proclaimed as official Church doctrine.

The filioque doctrine helped to justify the split of the Church and to prevent reconciliation of East and West, but the immediate cause of the schism revolved around Church politics.  As their temporal power grew, successive Popes became more aggressive in their claim to universal jurisdiction over the Church.  The Patriarch in Constantinople, on the other hand, argued that the Pope was merely one bishop amongst others, and that the Church should continued to be ruled by the heads of the five major patriarchates: Rome, Constantinople, Alexandria, Antioch, and Jerusalem (although in effect, Alexandria, Antioch, and Jerusalem, which were now in Muslim hands, had little say in the matter).  According to the Patriarchs a council of bishops was needed to determine important doctrinal issues.  In particular, the Patriarchs rejected Pope Benedict VIII unilateral alteration of the Nicene Creed in 1014 by the insertion of the filioque doctrine.

There were also an increasing number of liturgical and practical differences between the Western and Eastern churches, and as the name of the Orthodox Church implies, the eastern branch of the church generally maintained the traditional position in opposition to innovations stemming from Rome.  Important points of difference included the western introduction of unleavened bread into the Eucharist, the western practice of celibacy amongst priests (parish priest can be married in the eastern faith), and the eastern rejection of the worship of icons.

Matters came to a head in 1054, when Pope Leo IX sent Roman legates to Constantinople to deny Patriarch Cerularius the title of Ecumenical Patriarch (i.e. a universal religious leader on par with the Pope) and to insist that he recognize the Pope as the head of all the Church.  Cerularius refused and was promptly excommunicated by the head of the Roman delegation.  Not to be out done, he responded by excommunicating all of the delegates.  The schism between the Western and Eastern Churches had begun.  Greek anger over the Latin sack of Constantinople in 1204 only heightened the divide.  There were numerous attempts at reconciliation, including official declaration of Union in 1274 and 1439.  This second declaration of Union is the one that Constantine finally had enacted in December of 1452, just before the Turkish siege of Constantinople started.  The Union officially accepted the western doctrines of filioque and the supremacy of the Pope.  If the people of Constantinople had managed to fight off the Turks and hold the city, then it is possible that this union could have held, and the Western and Eastern churches would be one, even today.  But the city fell and with it all possibility of union.  In 1484, the union celebrated in 1452 was officially repudiated.  The schism became permanent, leading to the separate Catholic and Orthodox churches that we know today.

In the early drafts of Siege, I delved a bit more into these theological and political issues.  So to conclude, I’ll leave you with a scene from one of these early drafts…

Dinner that night was a small affair, held in the Pope’s private dining room around a table that accommodated only ten guests.  The room was decorated on three sides with frescos depicting the deaths of saints, and the paintings seemed to come alive under the flickering candlelight.  The fourth side of the room was lined with arched windows looking out on the lights of Rome, burning bright in the cold, clear February sky.

The Pope sat at the head of the table with his guests of honor—Sofia and Filelfo—to his right and left.  The rest of the guests were cardinals and bishops, and other than Bessarion, who sat to her right, Sofia did not recognize any of them.  The meal itself was elaborate.  The table was set with silver, gold, and crystal—a sharp contrast to the plain wooden dishes that served the Byzantine court—and the menu proceeded with course after course, each accompanied by its own wine.

Seated between the Pope and Bessarion, Sofia could not help but join in their theological debates, even if all she could think about was whether or not the Pope would call the Synaxis’s bluff.  They discussed the filioque, the main point of theological disagreement between the Catholic and Orthodox Churches.  The Pope defended the filioque, an addition to the Nicene Creed made in the year 589, which stated that the Holy Spirit proceeded from both the Father and the Son.  Bessarion represented the Greek Orthodox position, arguing that the Holy Spirit proceeded only from the Father.  Sofia mostly kept silent, marveling that men could argue so passionately over a few words.  When she said as much to Pope Nicholas, he smiled.

“Not just words, Sofia,” he replied.  “It is souls that are at stake.  If the Holy Spirit proceeds only from the Father and not the Son, then the Son is clearly less than the Father.  What then becomes of the Trinity?”

“There is no Trinity in your doctrine either,” Bessarion countered.  “For if the Holy Spirit proceeds from the Father and the Son, then there would have to be two sources of divinity.”

“Not at all.  The Spirit proceeds from the Father and the Son as from one divine principle.”

“But how can two be one?” Bessarion asked.  “There can be only one God, one divine.”

“I do not mean to advocate two sources of the Spirit,” the Pope explained.  “But how can the Spirit proceed from the Father without the Son?  Take the ewe and the lamb.”

“The what?” Sofia asked, not sure that she had heard correctly.

“The ewe and the lamb,” Nicholas repeated.  “Milk originates in the ewe, but it proceeds to the lamb.  Without the lamb, the milk would not flow.  Both ewe and lamb are necessary: one to produce, the other to receive.  Now, the Holy Spirit is the milk that flows from God to Christ, and through him to all mankind.”

“I see,” Sofia said, although she was not sure that she did.  She understood the first part of the analogy well enough, but if the Spirit flowed through Christ to all mankind, then did that mean that the milk likewise flowed from the lamb to men?  Clearly, that made no sense, unless perhaps one considered eating the lamb to be partaking of the milk.  Somehow, Sofia did not think that Nicholas was suggesting they eat the Son of God.  Or perhaps that was the purpose of the Eucharist?

Bessarion was expounding upon a similar idea.  “Lambs do not produce milk,” he pointed out.  “Nor can the Son produce the Spirit.  God only is the origin of the Spirit and the Son.  Christ is begotten of the Father, and the Spirit proceeds from the Father alone.”

“Begotten, proceeds, what is the difference?” Sofia asked.

“The difference, my dear, is beyond the understanding of men.”

Nicholas seized on this, thumping the table excitedly for emphasis.  “If the difference cannot be understood, then how can the filioque be denied?  Could the Father not beget the Son by sending the Spirit through him?”

“Yes, but the Spirit proceeding from the Father through the Son is not the same at all as it proceeding directly from the Son,” Bessarion pointed out.

“Ah, but you admit that the Spirit comes from the Son!”

“I admit no such thing!”

The two men laughed and then happily continued their debate, moving on to discuss Aquinas’s theory of spiration.  As the evening dragged on with no mention of union, and fatigue from the long day of traveling caught up to her, Sofia’s mind drifted away from the conversation.  She found herself thinking of Longo.  She wondered what he was doing now; no doubt sailing back to Genoa with his young betrothed.  She wondered what he thought of her after last night, and at the same time, wondered why she should care so much.  She had never paid much attention to men.  She had little reason to do so.  Most of the men she knew were pigheaded fools who looked at her only as potential property.

Why then this fixation with Longo?  She would probably never see him again.  Yet, she couldn’t help but think of him—his worn, handsome face; his strong, confident presence.  She wondered if this was what falling in love was like.  But how could she be in love with a man that she barely knew?

Sofia was brought back into the present by a sharp dig in the side from Bessarion.  To her embarrassment, she realized that Pope Nicholas had just asked her a question, which she had ignored completely.  “I fear you were somewhere else for a while, Princess,” Nicholas said, smiling.  “Perhaps you were contemplating the beautiful logic of Aquinas.”

Sofia blushed.  “Something very like, yes your Eminence,” she murmured.

“A great thinker indeed, though not without his faults,” Nicholas continued.  “After all, God does not always obey the dictates of logic.  Nor do men.  Take, for instance, the Synaxis in Constantinople.”  The Synaxis at last, Sofia thought.  The blush faded from her face and all thoughts of Longo from her mind.  They had reached the crucial point.  “I could grant the demands of their letter—a letter, I might add, written without the consent of the Patriarch of Constantinople—but I fear that even that might not appease them.  They are men ruled more by pride than reason, fueled by hatred rather than religion.  And if they still refuse union, then I will have humbled the Church for nothing and perhaps ruined any chance of ever achieving a true union.”  Assent echoed quietly down the table.  Only Bessarion kept quiet.

“What you say is true,” Sofia replied.  “The Synaxis might still reject union, even if you accept all their demands.  But if they do, they will not only be contradicting themselves, they will also be defying the Emperor.  Agree to some of the demands of the Synaxis and the Emperor will be free to force the Union through, even if he has to remove every bishop in the Synaxis.  And the bishops would not be able to truly complain, for after all, they have already agreed to union on these terms by signing the letter.”

“If only I could be as sure as you are, Princess, that Emperor Constantine would indeed enforce the Union even over the complaints of his clergy,” Nicholas replied.

“If Leontarsis were not ill, I am certain that he would be here to pledge the Emperor’s word,” Sofia replied.  “But, since he is not, I will pledge it myself as ambassador of Constantinople.”

“I have spoken with Leontarsis,” Filelfo said, speaking up.  “In his absence, I feel confident in guaranteeing the Emperor’s support of the Union for him.”  He gave Sofia a meaningful glance, and she offered a silent prayer of thanks for Leontarsis’s absence.  He would have promised no such thing.

“Very well then,” Nicholas said.  “I believe that the matter is more or less settled.  When the details are sorted out, I shall hold an audience at which I shall issue a decree recognizing the desires of the eastern bishops and looking forward to the true union of the Catholic Church in short time.  I do hope that Leontarsis will be well enough to attend that meeting.”  Nicholas smiled and even winked.  Clearly, the true reason for Leontarsis’s absence was not a mystery to him.  “In the meantime, let us begin dessert, and there is a question that I have for you, Princess, concerning our friend Aquinas…”

Sofia smiled.  Now that union had been secured, she would gladly discuss Aquinas, or any other philosopher for that matter.  Perhaps she could not fight to defend Constantinople, but Sofia knew that she had done much more than that here in Rome.  Helena would be proud of her she knew, and the Synaxis would be furious.  In the back of her mind, Sofia could not help but wonder what Longo would think.