Islam was founded in Arabia by Muhammed between A.D. 610 and A.D. 632. There are an estimated 5.4 million Muslims in Northern America and 1 billion Muslims worldwide. Muhammed was born in A.D. 570 at Mecca and belonged to the Quraysh tribe that was active in caravan trade. At the age of 25 he joined the caravan trade from Mecca to Syria in the employment of a rich widow, Khadiji, whom he later married. Critical of the idol worship of the inhabitants of Mecca, he began to lead a contemplative life in the desert. There he received a series of revelations or divine truths. Encouraged by Khadiji, he gradually became convinced that he was given a God-appointed task to devote himself to the reform of religion and society. He believed that the worship of idols was to be abandoned.
The Hegira (Hijra) (emigration) of Muhammed from Mecca, where he was not honored, to Medina, where he was well received, occurred in 622 and marks the beginning of the Muslim era. In 630 he marched on Mecca and conquered it. He died at Medina in 632. His grave there has since been a place of pilgrimage.
Muhammed's followers, called Muslims, revered him as the prophet of Allah (God), beside whom there is no other God. Sources of the Islamic faith are the Qur'an, regarded as the uncreated, eternal Word of God, and tradition (hadith) regarding sayings and deeds of the prophet. Islam means surrender to the will of Allah. He is the all-powerful, whose will is supreme and determines humanity's fate. The Five Pillars, or primary duties, of Islam are: profession of faith; prayer, to be performed five times a day; almsgiving to the poor and the mosque (house of worship); fasting during daylight hours in the month of Ramadan; and pilgrimage to Mecca at least once in a Muslim's lifetime.
Islam, upholding the law of brotherhood, succeeded in uniting an Arab world that had disintegrated into tribes and castes. Islam is the principal religion of the Middle East, Asia, and of the northern half of Africa.