How Islam Spread Across Three Continents in Just Over a Century
Islam emerged in the 7th century CE and has been growing ever since. It now counts nearly 2 billion followers worldwide, making it the second-largest religion on earth. But that number didn’t come from a slow, gradual process. Most of the geographic territory Islam occupies today was reached within roughly 140 years of Muhammad’s first revelation.
On the map above, created by the OER Project team, each shade represents a different phase of expansion, starting with the territories Muhammad himself brought under Islam between 622 and 632 CE, through to the spread of the faith into Sub-Saharan Africa and Southeast Asia between 1300 and 1700. There’s also a red-hatched area marking the Iberian Peninsula, where Islam was eventually expelled after nearly 800 years.
Muhammad received his first revelation in 610 CE at the age of 40, while meditating in a cave on Mount Hira near Mecca. For the next decade he preached mostly in private, gathering a small group of followers while facing sustained opposition from Mecca’s ruling Quraysh tribe. The turning point came in 622 CE with the Hijra, his migration from Mecca to Medina, which marks the start of the Islamic calendar. From Medina, Muhammad built both a religious community and a political state, and in 630 CE he returned to Mecca with an army of around 10,000 converts and took the city with minimal resistance. Two years later he was dead, but by then most of the Arabian Peninsula had converted to Islam.
What followed under his successors moved extraordinarily fast. Abu Bakr, the first caliph, ruled for only two years (632-634 CE) but launched the campaigns that would push Islam beyond Arabia. Under Umar ibn al-Khattab (634-644 CE), Arab armies defeated both the Byzantine and Sassanid empires and took Syria, Mesopotamia, Persia, and Egypt. Uthman and Ali (644-661 CE) continued that expansion further into Persia and North Africa. Then the Umayyad Caliphate (661-750 CE) pushed it to its most dramatic geographic extent, reaching the Iberian Peninsula in the west and the borders of India in the east.
After 750 CE, the Abbasid Caliphate replaced the Umayyads, and direct military conquest gave way to other means of spreading the faith. Trade networks carried Islam deep into Sub-Saharan Africa from the 12th century onwards, and Sufi missionaries were especially effective in South and Southeast Asia, where their more mystical, inclusive approach found receptive audiences. The Ottoman Empire, founded around 1299 by the Turkoman leader Osman I in northwestern Anatolia, became the next great vehicle for Islam’s spread, pushing deep into southeastern Europe and eventually absorbing much of the Middle East and North Africa as well.
The Iberian Peninsula is the notable exception on this map. Muslim armies crossed from North Africa into Spain in 711 CE and quickly controlled most of the peninsula. But they were never fully expelled. The Reconquista concluded in 1492 with the capture of Granada by the Catholic Monarchs, ending Muslim rule on the Iberian Peninsula. Between 1492 and 1610, approximately three million Muslims emigrated or were driven out of Spain. That red-hatched area on the map is the only part of the western Islamic world that was permanently reversed.
Timeline of Islam’s Spread
| Period | Year | Event |
|---|---|---|
| 7th Century | 610 CE | Muhammad receives his first revelation in the Cave of Hira, Mecca |
| 622 CE | The Hijra: migration from Mecca to Medina; start of the Islamic calendar | |
| 630 CE | Muhammad conquers Mecca; Kaaba cleared of its 360 idols | |
| 632 CE | Death of Muhammad; Abu Bakr becomes first caliph | |
| 633-651 CE | Arab armies defeat the Sassanid Empire; Persia brought under Islamic rule | |
| 8th Century | 711 CE | Islamic armies cross into the Iberian Peninsula |
| 750 CE | Umayyad Caliphate replaced by the Abbasid Caliphate | |
| 11th Century | 1071 CE | Seljuk Turks defeat Byzantines at Manzikert; Islam expands into Anatolia |
| 12th Century | 12th century | Islam spreads into West Africa through trade and missionary activity |
| 13th-14th Century | c. 1299 CE | Ottoman Empire founded by Osman I in northwestern Anatolia |
| 15th Century | 1453 CE | Ottomans capture Constantinople, ending the Byzantine Empire |
| 1492 CE | Fall of Granada; Reconquista complete; Islam expelled from the Iberian Peninsula | |
| 16th Century | 16th century | Islam becomes dominant in much of Maritime Southeast Asia, particularly in present-day Indonesia and Malaysia |
| 21st Century | Present | Islam has approximately 2 billion followers worldwide, the world’s second-largest religion |
The religion Muhammad founded didn’t stay unified for long. The question of who should lead the community after his death in 632 CE split his followers into two branches that have remained distinct ever since. Sunnis accepted Abu Bakr as the rightful successor, while Shia Muslims believed leadership should have passed to Ali, Muhammad’s cousin and son-in-law. Sunni Islam accounts for roughly 85-90% of Muslims worldwide today, while Shia Islam represents about 10-15%, with large concentrations in Iran, Iraq, and Lebanon. Smaller branches, including the Ibadi tradition centered primarily in Oman, and the Ahmadiyya movement that began in the Indian subcontinent in the late 19th century, account for the remainder.
A faith that didn’t exist in 600 CE had reached three continents before 750 CE, and has continued expanding through trade and missionary activity ever since. It’s one of the most rapid religious expansions in recorded history.
For those interested in exploring more about the spread of Islam and related topics, consider these recommended items available on Amazon:
- Islam: A Short History: A concise and accessible introduction to the history of Islam by Karen Armstrong.
- The Oxford History of Islam: A comprehensive history of Islam from its origins to the modern era.
- Rand McNally Classic World Map Poster: A detailed and educational world map poster perfect for studying historical expansions and cultural influences.
