The First Crusade was successful, though at a terrible cost in lives and fortunes. The European nobles set up two “kingdoms” in the area of the Holy Land: Jerusalem and Edessa. What some people apparently failed to notice, at the time, was that there were actually two enemies of Byzantium and the Eastern Roman Empire, and focusing on Jerusalem and the Arabs may have been responsible for letting the much greater threat, the Turks, in at the back door. Both were Muslim, but that was where the similarity ended. For one thing, the Turks had learned to make deals with the Byzantines, who, it will be remembered, didn’t care for the westerners even a little bit.
So, the County of Edessa, having been established in 1099, soon came under Turkish attack. Many suspect that the Byzantine emperor at the time supported the Turks. In any case, Edessa fell, and the Pope called for a Second Crusade, to take it back. Two armies marched to Constantinople and were let through the city. They attacked the Turks and were soundly defeated by 1148. The only success of the Second Crusade was in Portugal, where an army of Brits, Scots, Germans and Norman French stopped off and threw out the Muslim ruler, thus bringing Portugal back under Christian rule.
Eventually, a Third Crusade was called to finish the work of the Second, and it was largely successful, though Jerusalem itself was not recaptured. Before that could happen, Frederick Barbarossa, the Holy Roman Emperor, himself, who was there4 to lead the assault, died unexpectedly, throwing the German troops and others into despair, and thus ending the Crusade, itself.
A Fourth Crusade was called, this time planned to cross the Mediterranean, capture Egypt, and move north to take the Holy Land. The beauty of this plan was that it solved the “two-front” problem that all the other Crusades had faced. If they could take Egypt , first, they had a very good chance of “rolling up” the Turkish forces and approaching Constantinople from the South. Unfortunately, the best laid plans may often go awry, as we’re told by Robert Burns (actually he said “schemes”, but you get the point), and that’s what happened to the Fourth Crusade. More about that, next time.
But in the meantime, what’s all this have to do with the Church? Well, remember: the jobs of the Roman Church and the Holy Roman Emperor, in the West, were closely interrelated, as were those of the Ecumenical Patriarch and the Emperor of the Eastern, or Byzantine, Empire in the East. And, just as the Popes were excommunicating each other, the Emperors saw one another as rivals, as well. More than once, differences in religion caused political strife and vice-versa.