By the beginning of the Middle Ages (6th cent.), Christians had a general understanding that all theological disputes should be solved by representatives of the five major Christian regions: Jerusalem, Antioch, Alexandria, Constantinople and Rome. After the fall of the Roman Empire, Constantinople considered itself the Roman government in exile. When Roman Popes began crowning Carolingians as Holy Roman Emperors in the west, it was a direct assault on Constantinople’s claims. Around the same time three of the five Patriarchates fell under Islam’s rule: Alexandria, Jerusalem and Antioch no longer had secular power, though they could still send theologians to a council. The power struggle between Rome and Constantinople had no mediating parties: it really came down to Eastern “Rome” vs. a resurgent Rome.
When the Franks and other Europeans converted to Latin Christianity, they learned a form of the official creed that included a word not used in Byzantine churches. Rome didn’t officially adopt this version until 1014, when it was sung at the coronation of Henry “the Fowler” as Holy Roman Emperor. During the 800s and 900s, it was a football to kick around, a negotiating point while Rome and Constantinople bickered over other forms of power.
At one point, the Byzantines politely informed the Latins that they had deposed their Patriarch. Rome responded by sending an inquiry team as if Constantinople needed Rome’s approval. At missions frontiers, Greek and Latin missionaries clashed. Russia went Greek; Poland went Latin. Hungary went Latin. Bulgaria was a battleground with both kinds of missionaries, but by 1020, Byzantium was in military and theological control of Bulgaria and Serbia.
When Normans began to take over southern Italy, they appointed Latin bishops who used the Western creed form. Italy shared the peninsula with Rome, but southern Italy (mostly Mediterranean coast with shipping ties to the east) had always answered to Constantinople. Southern Italians were confused. Who was in control? Was it a collegiate matter for a church council, or had there been conquest? Was Rome now higher than a sibling? Yes: the “Bishop of Rome” now claimed to have theological hierarchy over all other regions.
The Patriarch of Constantinople retaliated against Rome’s abuse of power by closing Latin churches still operating in his city in 1052. In 1054, a legate from the Pope walked into Hagia Sophia Basilica and laid on the altar an order of Excommunication against the Patriarch. For a few decades, Patriarchs had often “forgotten” to list Popes in their official church hierarchy list; on their side, the Popes often “forgot” to notify Constantinople of their ordination. Now they were openly declaring each other powerless and illegitimate. The excommunicated Patriarch ignored the Papal Bull and issued his own edict denouncing the heretical Latin creed formula.
So what happened next? Not much. In a way, the Great Schism mattered less in its own time than it does now. At the time, Greek-speaking Anne of Kiev was queen of France and then regent over her son Philip. The Holy Roman Emperor didn’t come around arresting Byzantine relatives at the Parisian court just because Rome had issued an edict. And one generation later, in 1081, the western (German) Holy Roman Emperor was himself besieging Rome in a dispute with the Pope. It wasn’t even clear if the Pope was his own man.
What we can learn from it, coming up to the Crusades, was the fluidity and uncertainty of relationship between Rome and Constantinople. We all know as a point of general information that the First Crusade happened because the Pope sent help at request of the Byzantine Emperor. We’ll get there shortly, as the 11th century closes. But think about the geopolitical significance of what amounted to a Latin military invasion of Byzantine territory. At the same time that Normans were oppressing Greek monks in Italy, the Greek Emperor was forced to invite more Normans right into Jerusalem to do the same. Imagine the delight of the Pope, after two centuries of power plays against Byzantium: now, he had the ability to summon a chain-mailed horde to the rescue.
We tend to look back in history and assume that Rome was always dictating to Europe; but instead, we see here that a process of elimination (Islam taking over competitors) and long rivalry led to that point. Until that point, it wasn’t clear that Rome was really going to become All That. The Bishop of Rome was just a church official in a city among others. But the First Crusade was a master stroke of sibling domination. It was the first reply to Stalin’s much later question: How many divisions does the Pope have? 11th century answer: more than the Patriarch, anyway.