After the formation of the Nestorian and other heretical sects, the orthodox faith was preserved in the East only by the Greeks of Asia Minor and Europe. The Greek Church, which calls itself the "Holy Orthodox Church," for a time remained in unity with the Roman Church in the West. The final separation of these two churches occurred in the eleventh century. [12] 122. WESTERN CHRISTIANITY: RISE OF THE PAPACY THE PAPACY Christianity in the West presented two sharp contrasts to eastern Christianity. In the first place, the great heresies which divided the East scarcely affected the West. In the second place, no union of Church and State existed among western Christians. Instead of acknowledging the religious supremacy of the emperor at Constantinople, they yielded obedience to the bishop of Rome, the head of the Roman Church. He is known to us as the pope, and his office is called the Papacy. We shall now inquire how the popes secured their unchallenged authority over western Christendom. [Illustration: PAPAL ARMS According to the well-known passage in _Matthew_ (xvi, 19), Christ gave to St. Peter the "keys of the kingdom of heaven," with the power "to bind and to loose." These keys are always represented in the papal arms, together with the tiara or headdress, worn by the popes on certain occasions.] ROME AN APOSTOLIC CHURCH A church in Rome must have been established at an early date, for it was to Roman Christians that St. Paul addressed one of the _Epistles_ now preserved in the New Testament. St. Paul visited Rome, as we know from the _Acts of the Apostles_, and there he is said to have suffered martyrdom. Christian tradition, very ancient and very generally received, declares that St. Peter also labored in Rome, where he met a martyr's death, perhaps during the reign of the emperor Nero. To the early Christians, therefore, the Roman Church must have seemed in the highest degree sacred, for it had been founded by the two greatest apostles and had been nourished by their blood. ROME A "MOTHER-CHURCH" Another circumstance helped to give the Roman Church a superior position in the West. It was a vigorous missionary church. Rome, the largest and most flourishing city in the empire and the seat of the imperial government, naturally became the center from which Christianity spread over the western provinces. Many of the early Christian communities planted in Spain, Gaul, and Africa owed their start to the missionary zeal of the Roman Church. To Rome, as the great "Mother-church," her daughters in western Europe would turn henceforth with reverence and affection; they would readily acknowledge her leading place among the churches; and they would seek her advice on disputed points of Christian belief or worship. THE ROMAN CHURCH INDEPENDENT