There was strong rivalry between the bishops of these two renowned cities, each struggling for the pre-eminence. The Bishop of Rome gradually assumed the title of Papa, or Pope. Indeed, in the first century, all the bishops in the East were entitled Pope, or Father. Subsequently, in the fifth century, the Bishop of Constantinople took the title of Patriarch. The strife eventuated in a division between the Greek and Roman churches. The Pope at Rome took the Western churches, and the Patriarch at Constantinople the Eastern. Swaying the sceptre of spiritual power, both of these ecclesiastics gradually grasped temporal power also. Christianity was virtually banished from the Church, though there were here and there devoted pastors; and thousands of Christians, some of them even in the highest walks of life, were, with prayers and tears, struggling, through the almost universal corruption, in the path to heaven. Both the Grecian and the Roman hierarchies became mainly but ambitious political organizations, ministering to pride and luxury and splendor. There were some good popes, as there have been good kings; and many bad popes, as there have been bad kings. It was near the close of the sixth century that Mohammed commenced his marvellous career. Whether this extraordinary man were a self-deceived enthusiast, or a designing impostor, is a question which will probably ever be discussed, and never settled. Born of wealthy parents in the city of Mecca, in the interior of Arabia, about the year 569, he, when a lad of but thirteen years of age, travelled to Syria on a commercial expedition. Here he was entertained in one of the Christian monasteries,――almost the only resort of travellers in those days. One of the fathers, perceiving in him indications of genius, paid him marked attention, and probably made strenuous exertions to secure his conversion, not only to Christianity, but to the superstitious observances which had grown up around the pure religion of Jesus. All great men are of a pensive temperament: the tremendous mystery of human life oppresses them. Young Mohammed was thoughtful, contemplative, with a tinge of melancholy pervading his whole character. It is evident that he was much impressed by the scenes which he had witnessed and the instructions he had received in the convent; for he formed the habit of retiring every year to the Cave of Hera, about three miles from Mecca. Here, in a natural cloister, he annually spent a month in solitude, meditation, and prayer.