Islam, the religion based on the teachings of the Prophet Muhammad, is most commonly associated with the Middle East. Although the religion started in the Middle East, it has spread around the globe. Today, the largest populations of Muslims (followers of Islam) are found in Southeast Asia, the Middle East and Sub-Saharan Africa. Europe also has a significant Muslim population, and the number of Muslims in the United States is growing.
Early Islam was centered around two cities in what is now Saudi Arabia. The Prophet Muhammad was born and lived in the city of Mecca. This is where he first began receiving divine revelations in the year 610. About eight years later, Muhammad moved to the Arabian city of Medina. Today, Mecca and Medina both remain holy cities. In fact, devout Muslims face the city of Mecca every time they pray. During Muhammad's life, Islam spread throughout the Arabian peninsula, and after his death in 632, it began to spread more.
Islam's Spread Outside of Arabia
Soon after Muhammad's death, Islam began to spread outside the Arabian peninsula. A formal army was formed and began the Arab conquests in order to conquer new lands for the Islamic empire. Initially, the religion spread to the areas that were closest. By 638, Islam had spread north of the peninsula into what is now Syria, Palestine, Lebanon and Iraq. Even today, Islam is the main religion in these countries.
By 641, the army had entered Egypt, and by the mid-650s, the Islamic world extended throughout most of Northern Africa. Islam slowly spread throughout the African continent over the next 400 years. By the year 1000, Nigeria was an important Muslim trade site connecting Northern and Southern Africa.
Islam In Europe and Asia
The success of the expansion of Islam continued even after most of the Middle East and Northern Africa were conquered. New Muslim states were established in both the east and west. In 711, the Arab conquests came to what is now Spain. In just two years, most of the Iberian Peninsula (now Spain and Portugal) was under Islamic control. It would remain that way until Christian armies slowly began reclaiming territory during the Crusades in the Middle Ages. By 1492, Spain was entirely under Christian control again, and Muslims were expelled.
At the same time that the Muslim army was entering Spain, the Islamic empire was also expanding into India. From there, the religion spread throughout Southeast Asia, since trade routes in the region were controlled by Muslims. Today, Southeast Asia, including Indonesia, Malaysia and the Philippines, has the largest Islamic population in the world, containing more than 60 percent of the world's Muslims.