who wanted to study it, complains that he must first learn "the hard language of the Romans."^[1] But since Justinian even Law was written in Greek, and from that time there were very few Greeks who could speak Latin. Peter of Antioch received a letter from Pope Leo IX (1048–1054)^[2] and he had to send it to Constantinople to have it translated. Even Photius, the most learned man of his age, could not understand Latin. On the other hand, Pope Vigilius (540–555) spent eight unhappy years at Constantinople, but amid his troubles he never learned Greek. The Popes kept a perpetual Legate, the Apocrisarius, at the Emperor's Court since the time of Justinian; but even these Legates generally knew no Greek. St. Gregory the Great († 604) had been Apocrisarius at Constantinople, but he never knew any language except Latin. This difference of language was a very serious hindrance to the mutual influence that would have prevented the Churches from drifting apart.^[3] And so, since the Pope and his Latin Court were so strange to these Greeks, since his intervention was rare in their affairs, it must have often seemed to them, when he did stretch out his arm across the seas, that he was interfering unduly in their business. One can imagine an Eastern bishop, such as Theophilus of Alexandria, for instance (p. 69), who was congratulating himself on having triumphed, suddenly finding that his arrangements were all reversed by the result of his adversary's appeal to Rome, and thinking in his disappointment: Why cannot the Roman Patriarch let things alone?

But undoubtedly the chief cause of all ill-feeling was the ambition of Constantinople. We have seen how the bishops of that city step by step climbed up to the first place in the East; how easily they displaced the other Eastern Patriarchs; how they could always count on the help of the Emperor; and how the adversary, who always stood in their way, was the Pope. They could not pretend to ignore him, and at each step they foresaw his certain opposition. It was most of all in the minds of the Œcumenical Patriarchs that anger and jealousy