At very time when Gregory the Great was turning away from the Eastern Mediterranean and seeking to extend papal control over the West, there began in Arabia the career of a religious leader, Muhammad of Mecca (about 570-632 A.D.). His teachings had an immediate impact and the movement of Islam which he started spread with dramatic speed outside Arabia after the prophet's death. Muhammad (or Mahomet or Mohammed) was born about 570 A.D., five years after the death of Justinian. He was orphaned at an early age and raised by his uncle, a merchant of Mecca. He assisted his uncle in the caravan trade (as a camel driver) and conducted himself very much as other young merchants did, except for one execption. Once a year he went off to be alone with his thoughts. It was not considered eccentric and he did not arouse undue attention by his annual retreats. Going with his uncle on trips to Syria and Palestine, he came in contact with Christianity and Judaism. In 594 A.D. Muhammad was employed as business manager by a rich, prominent merchant of Mecca, a widow woman named Kadija or Khadijah. This merchant was quite pleased by his management of her business. But even more, she was attracted to Muhammad as a man. Through a friend she inquired about the young man's marriage prospects and found that he was not otherwise engaged. And so, through the same intermediary, Kadija proposed marriage to Muhammad and he accepted; marriage soon followed. The new bride was some fifteen year older than the groom, but the marriage was a happy one; until her death in 619 A.D., she remained his only love. Kadija was sympathetic with Muhammad's lonely retreats and her wealth made it possible for him to devote more and more time to finding answers to questions that troubled him. During one of Muhammad's vigils on Mount Hira the place of his retreats a trance came upon him which revealed a new focus for all things. He was convinced that Allah was an all powerful God and all things should be made to conform to his will. Similar trances followed in which other revelations were made, consistent with the principle that all things must be made to conform with the will of Allah. Like others who had been converted, Muhammad began to persuade others to his new teachings and so he began to preach to his fellow Meccans. But for the most part the men of Mecca did not accept his teachings; they suspected that a single god might be tyrant and they feared that Muhammad's condemnation of their gods in the Ka'bah would injure the lucrative business which pilgrims brought to the city. Tribal warfare was frequent among the Arabs except during the periods of truce each year when the tribes went to worship the black stone in the Ka'bah at Mecca. Even twelve years after his conversion, his followers were few, mostly among his own kinsmen.
Two hundred and fifty miles north of Mecca is the Arabian city of Medina, also a trading city situated in the fertile fringe near the Red Sea. Between 620 and 622 A.D., some of Muhammad's followers slipped away to Medina and spread the new religion there. In 622 A.D. Muhammad was waited upon by a delegation of seventy citizens of Medina, who invited Muhammad to become the religious and political governor of their city. There was strife in Medina and it was believed that a resolute outsider might quell the disorder. Muhammad accepted this offer, leaving his own city of Mecca in 622 A.D. He left hurriedly and, at one point, had to hid in caves from his enemies. His enemies were those who had rejected his teachings and now regarded his departure with much distrust. The flight from Mecca has been called in Islam as the Hijrah (Hegira) and from it the Islamic calendar is dated. Muhammad restored order in Medina, sometimes with harsh measures, and he also spread his teachings. He was careful at first to welcome to his cause the large number of Jews who lived in the city; he wanted their support and, besides, he regarded himself as a reformer not only of the Arabian faith but also of Judaism and Christianity. The Jews, however, did not respond and Muhammad's attitude hardened against them.
Both the creed and ritual of the new religion is set forth in the Islamic "Bible", called the Koran or Qur'an, a term applied at first to each individual revelation and then to the whole compilation of them by Muhammad's successor. This work, about two thirds the length of the New Testament, is arranged in 114 chapters. The longest chapter comes at the beginning of the book, and the chapters become successively shorter until the last chapter contains only three verses. It is repetitious and unorganized. The belief in one God known as Allah is the central teaching of the Koran. The basic confession of Islam is that "There is no god but Allah, and Muhammad is his prophet". The basic belief of Islam is that Allah is the only God and Muhammad is his final prophet. Its basic moral principle is "surrender to the will of Allah," or Islam, and "those who have submitted to Allah" are Moslems. The Arabic word "Islam" means "submission" or "obedience". There is no claim to divinity by Muhammad, not even to that combination of divine and human natures as affirmed of Jesus Christ. Muhammad believed that Allah had made his will known through twenty-eight prophets, including Jesus, Alexander the Great, and the twenty-five Old Testament characters such as Abraham and Moses; but Muhammad is latest and greatest of these prophets. Muhammad denied the deity of Jesus Christ and his death and resurrection for man's salvation. Muhammad was influence by the Christian Monophysite teaching about the person and work of Jesus Christ. Even though Muhammad rejected the divinity of Christ, he retained the Monophysite emphasis on the Virgin Birth and a belief that Jesus did not really suffer and die on the cross - a misunderstanding of the Monophysite Logos doctrine. The Islamic religion is fatalistic with its concept of passive submission to the will of Allah. After the judgment Muslims believe that men will either enjoy a sensual paradise or face the terrors of hell, according to whether they submit to the will of Allah or not. A faithful Muslim prays five times daily facing toward Mecca. He also recites his creed daily. On Fridays special services are held at centers of worship called mosques. Fasting during the sacred month of Ramadan, and almsgiving to the poor are also required. The devout Muslim must make, at least once during his life, a pilgrimage to Mecca. The Ka'bah remains the center of worship in the sacred city of Mecca; it was cleansed of its idols but the sacred stone has been retained. Islam forbids the making of images, and the ornamentation of the mosque is restricted to patterns and elaborately carved texts from the Koran. Islam, in spite of its dependence on ritual, was a religion without priests, or at least without a priestly class. Administration of Islam was centered in Muhammad and those who succeeded him. Administrative assistants were necessary, of course, but they ruled as lay officials in the Islamic theocracy.
By 630 A.D. the movement had grown so much that Muhammad was able to capture Mecca. Two years later, at the time of his death, his followers were ready to expand outside the Arabian Peninsula. The greatest expansion of Islam took place between 632 and 732 A.D. Syria and Palestine were won by 640 A.D., and the Mosque of Omar was soon erected in Jerusalem. Egypt was won in the next decade, and Persia fell under Islamic control by 650 A.D. The crescent-shaped expansion to the West and to the East threatened Christianity with a great pincers, but expansion at the eastern end of the crescent was stopped by the brave defense of the Eastern empire under Leo III, the Isaurian, in 717 and 718 A.D. Muslim expansion on the Western end of the crescent was halted by the defeat of the Muslims by the armies of Charles Martel at Tours in 732 A.D. The conquered peoples were usually faced with the choice of submit or die. Muslims were not always intolerant, however, for they often permitted the people to pay tribute and continue to practice their faith. By 750 A.D. the era of conquest came to an end, and the Muslims, influenced by Greek culture, set out to build an Arabic civilization centered in Baghdad. The peak of culture came under Haroun-Al-Baschid (786-809 A.D.), the ruler of the eastern section of the Muslim territory.
Islam has had a marked cultural and religious influence on Medieval Western Europe. Islam assimilated and passed on to Western Europe through Arabic Spain the Greek philosophy of Aristotle. Greek manuscripts were translated into Arabic. And this became the chief function of the Alexandrian scholars after Egypt was conquered by Islam and the Alexandrian library was burned in 642 A.D. In the Baghdad School (established in 832 A.D.) the Arabic interest in science lead to the translation of the writings of Aristotle. The Baghdad School translations of Plotinus's Enneads, Books 4 to 6, titled The Theology of Aristotle, were improperly attributed to Aristotle. This was responsible for the Neoplatonic misinterpretation of Aristotle which was not corrected until the 13th century. Arabic mysticism fostered interest in Platonism and Neoplatonism. The great Islamic philosophers appeared in the 9th and 12th century: Al-Kindi (813-873?), Al-Farabi (died 950), Avicenna (980-1037), Avempace (died 1138) attempted to synthesize these interests into an Aristotelian NeoPlatonism. Averroes (1126-1198) spread Aristotle's influence by means of detailed commentaries. Al-Ghazzali (1058-1111), maintaining an orthodox and non-philosophical mysticism, criticized his predecessors, Al-Farabi and Avicenna, in his principal writings. He help establish the mystical tradition of Sufism, founding a school in that tradition.
The medieval scholastics attempted to integrate Greek scientific thought with Christian theology by the use of the deductive method of Aristotle, which they had come to know in Spain through Averroes's translation of the writings of Aristotle. So great was this influence in Europe during the twelfth century that Haskins called the period the "Twelfth Century Renaissance." [Charles H. Haskins, The Renaissance of the Twelfth Century (Cambridge: Harvard University Press, 1939)].
Both the Eastern and Western sections of the Church were weakened by the loss of people and territory to Islam. The West lost the strong North African church and the East lost both Egypt and the Holy Land. The Eastern churches were able to do little more than hold back the Muslim hordes from sweeping past Constantinople. Consequently, missionary activity, which was carried on mainly by the Western church, centered in northwestern Europe. The Eastern churches also had to deal with the problems of whether images as well as pictures could be used in the church. This became known as the Iconoclastic controversy and it came about partly because the Muslims were accusing the Christians of being idolaters, because they had pictures and images in their churches. This weakening of the Eastern churches allowed the bishop at Rome to strengthen his position in the universal or catholic church. Rival patriarchs of the church in Alexandria and Antioch were now under Islamic domination and were unable any longer to speak for the church at large. The pope was not slow to make the most this opportunity to strengthen his own position. Islam stubbornly resisted the efforts of the papacy and Crusaders to regain the Holy Land and since that time has strongly resisted every attempt of Christian missionaries to propagate Christianity among Muslims.