Islam (Arabic: “submitting oneself to God”), one of the major world religions, the youngest of the 3 monotheistic religions developed in the Middle East. Most of the more than 600 million followers of Islam, or Muslims, live in the Arab countries of southwestern Asia, in northern and eastern Africa, Turkey, Iran, Afghanistan, Pakistan, the Malay Peninsula, and Indonesia. There are also large numbers in the Soviet Union, China, India, and the Philippines. Islam was founded by Muhammad, who was born c.570 A.D. in Mecca. In his travels as a merchant he came to know the Christian and Jewish religions. After a period of meditation, during which he said the archangel Gabriel spoke to him, Muhammad began preaching in Mecca. He denounced the worship of idols and proclaimed that there was only one God (Allah, in Arabic) and that he was God's messenger to carry the teaching to the pagans. He angered many of the people of Mecca, who forced him to flee to Medina c.622. There, he gathered followers and returned to Mecca in 630 to wage a jihad (holy war). Islam was finally accepted by the Meccans, who called Muhammad their prophet. In the 100 years after Muhammad's death (632), Arab armies swept across Asia as far as India and across North Africa and into Spain, building the great Muslim Empire, spreading their religion and culture. The holy book of Islam is the Koran (Qur'an), which sets forth the fundamental beliefs of Islam as revealed by God to Muhammad. These include the 5 basic duties of every Muslim and the rules that govern moral behavior and social life. Muhammad's teachings, called Sunna, are collected in the Hadith (“traditions”). Together, the Koran and the Sunna provide instructions governing all aspects of the personal and communal life of Muslims. A system of law, the Shari'a, has been developed on the basis of the Koran and the Sunna. At various times, the Shari'a has been the law of many Muslim countries. Public worship is held in buildings called mosques. At midday every Friday special services are held. Before entering a mosque, Muslims must ritually wash themselves in the courtyard. The mosques are usually elaborately decorated, but no representations of animal or human figures are permitted because of proscriptions against idolatry. When praying, 5 times during the day, Muslims face in the direction of their holy city, Mecca. Worship is led by a lay religious leader called an imam. Traditionally, Muslims are called to prayer by a muezzin, who chants from a rooftop or from a minaret, a tall tower attached to the mosque. The 2 main sects of Islam, Sunni and Shiah, originated in the 7th century as a result of disputes over the succession of caliphs or religious rulers. Sunnites form the majority, while the large Shi'te minority predominates in Iran and has given rise to other smaller sects.