the religion of Muslims, revealed through Muhammad, the Prophet of Allah. The name comes from Arabic, meaning 'submission' to God. The cardinal principle of Islam is tawhid (making one), the absolute unity of God, Allah, the universal creator whose omnipotence is supreme. This is expressed in the shahadah: 'There is no god but Allah and Muhammad is his Messenger'. Human authority lies with a succession of prophets, of whom the most important are Noah, Abraham (regarded by Muslims as 'the father of Islam'), Moses, and Jesus, with Muhammad as the final 'Seal of the Prophets'. Islam has two major sects: Sunni and Shia Islam. Shiites revere Ali, the son-in-law of Muhammad, as the first successor of Muhammad. Divine origin and authority is attributed to the Koran, the 'recitation' of the word and will of God, as revealed by the Angel Gabriel to Muhammad and the Sunna (Muhammad's words and actions recorded by his companions but not written by him), while the political and social framework is provided by the sharia (the legal code of Islam). Religious practice is based upon observance of the Five Pillars of Islam: to accept the basic creed ('I testify that there is no god but Allah and that Muhammad is the prophet of Allah'); to offer prayers five times a day; to pay zakat, a charitable levy; to fast during daylight in the month of Ramadan; and, once in a lifetime, to undertake the hajj, the pilgrimage to the Kaaba at Mecca. Public worship occurs in a mosque, where prayer is led by an imam. Attendance at the mosque, which is not required of women, is compulsory for men on Fridays and special festivals and meritorious on all days. Moral and religious law is disseminated through the sharia, based on the Koran and the hadith, a canon of belief and social regulation. There are four schools of law in Sunni Islam; disputes have traditionally been resolved by aijma', or consensus. Islam does not recognize a clergy which intermediates between the individual and God; however, religious and legal officials exist to give leadership on matters of faith and doctrine, particularly within the Shia branch of Islam. Parallel to the formal practice of Islam is the Sufi or mystical movement through which an individual may experience direct intuitive awareness of God. Sufi fraternities such as dervishes form an important element in Muslim spiritual life and society.

In the 7th and 8th centuries, Muslim armies from Arabia, driven on by the concept of jihad (holy war) against unbelievers, spread the religion throughout the Middle East and North Africa and into Spain, creating a vast Islamic empire by the 9th century. By 1800 Islam was the official religion of the Ottoman empire, whose sultan was caliph. It had spread into sub-Saharan Africa, the Balkans, central Asia, the Indian sub-continent, and the East Indies. Today Islam is the official religion of approximately forty-five nations with some eight hundred million believers. New communities of Muslims have become established in all European countries as well as in North and Latin America, and it has been estimated that there are some seven million in Europe and twelve million in the republics that comprised the former Soviet Union. The course of African history in the 19th century was affected by Islamic movements among the Sanusi in Libya, the Fulbe and Fulani in West Africa, the Mahdists in the Sudan, all influenced by the Persian teacher, Jamal al-Din al-Afghani (1838-97). With the fall in 1922 of the Ottoman empire and the discontinuation of the caliphate (the temporal and spiritual leadership of the Muslim community) in Constantinople, a tide of Muslim nationalism emerged. The early 20th century witnessed two well-organized movements for the revival of fundamental Islamic beliefs and the countering of Western influences: the Society of Muslim Brothers (al-Ikhwan al Muslimun) founded in 1928 by Hasan al-Banna (1906-49) in Egypt, which has since spread throughout the Middle East, and the Islamic Society (jamma'at-i-Islami) founded in 1941 by Syed Abu al-Mawdudi (1903-79) in India. Both of these have influenced other Islamic movements across the world, including the movement initiated by Ayatollah Khomeini in Iran. All emphasize the social and political reconstruction of Islamic society and of the Islamic state. The two major groupings of Islam today are the Sunni, comprising the main community in most Muslim countries, and the Shiite, centred chiefly in Iran. Both adhere to the same body of tenets, but differ in community organization and in theological and legal practices. Central to these is the Shiite belief that only the descendants of the prophet Muhammad may adopt the title and role of imam (religious leader), while the Sunni choose the latter by consensus. The tensions between Sunni and Shiite have been a major cause of social and political unrest in Middle Eastern countries during the 20th century, while the rise of Islamic fundamentalism in many countries since the late 1970s has created a significant new element in world politics.