The short version: the phrase runs two questions together. The early Islamic empire was made by war; that is not in dispute. Whether the religion was spread by force is a different question, and on most of the evidence the answer is mostly no: conversion came slowly, through pressures and incentives rather than a general order to convert, and with episodes of coercion in particular times and places. Majority The phrase itself is a modern battleground, used by critics of Islam to describe the faith and rejected by many Muslims, who point to the Qur’an’s “There is no compulsion in religion” (Q 2:256).[1] Political What follows sets out the evidence on each side.
The empire was made by war
Between 634 and 651 Arab armies took Byzantine Syria, Palestine and Egypt and the whole of the Sasanian empire in Iraq and Iran (§4).[2] Consensus The conquests brought killing, captivity and enslavement, recorded by Christian witnesses of the time: a Syriac chronicler writing about 640 counts some 4,000 villagers of Palestine, “Christians, Jews and Samaritans”, killed in a battle near Gaza in 634 (How we know).[3][4] Consensus Later conquests, in Spain from 711, in Sindh from 711–712, and in north India from the eleventh century, were also wars.[5][6] Consensus
The Qur’an itself commands fighting the “People of the Book” until they pay tribute, the jizya (Q 9:29).[7] Consensus on the text. That is a command to subject, not to convert: tribute is the alternative to fighting, and paying it ends the war.
The conquered were not, in general, made to convert
Christian, Jewish and Zoroastrian communities that surrendered became protected subjects, later called dhimmīs, “people of the pact”. They kept their places of worship and their own law in internal matters, and paid a land tax and the poll tax. The terms varied, and the fixed legal categories of later centuries took time to form.[8] Majority
The Arab Muslims were a small minority in the lands they ruled, living largely apart in garrison towns, and the state depended on the taxes of non-Muslims. The early rulers had little reason to press conversion and some reason not to: converts claimed tax relief and stipends.[2][9] Majority Christian writers of the time complain of taxes, captives and violence, but rarely of forced conversion.[4] Majority A hostile Egyptian bishop, John of Nikiu, writing about fifty years after the conquest, records that the Arab commander “took none of the property of the Churches”, and condemns the Egyptians who had already “embraced the religion of the Moslem”.[10] Majority on what it shows: burdensome tribute, protected churches, and early, voluntary but socially charged conversion.
Umayyad governors short of revenue sometimes kept taxing converts as if they were not Muslims, and in places sent them back to their villages; ʿUmar II (r. 717–720) is remembered for ruling that converts were to be freed from the poll tax (§5).[11][12] Majority A state that discouraged conversion in order to keep its revenue is hard to square with a religion spread at sword-point.
How slow was conversion?
No census survives. Richard Bulliet, counting the generations at which Muslim names appear in family genealogies, argued for an S-shaped curve: slow conversion for a century, then rapid growth in the ninth and tenth, with a Muslim majority in Iran by around 900 and later elsewhere.[13] Majority that conversion was gradual; Contested on the pace, because his genealogies are those of urban elites. Jack Tannous argues that in Syria, Iraq and Egypt Christians remained a majority for many centuries.[14] Contested On either reckoning, the conquered lands became mostly Muslim over two to five centuries, not at the conquest. Majority
What drove it was mixed: lower taxes and access to power, marriage, slavery, the converts’ own conviction, and the slow weight of living as a tolerated but unequal minority.[13][14][9] Majority How much pressure the poll tax and the status of non-Muslims applied is itself argued. Political
Where coercion did happen
The record includes forced conversion, and an honest answer has to name it:
- The Almohads of North Africa and Spain, in the twelfth century, abandoned the old protections for Jews and Christians and pressed them to convert; many emigrated, among them the family of Maimonides (§8).[15][16] Majority
- The Ottoman devşirme took boys from Christian families, mostly in the Balkans, converted them and trained them for the army and the palace, from at least the fifteenth century (§9).[17] Consensus
- The Safavids imposed Shia Islam on a mostly Sunni Iran from 1501: Sunni scholars were killed or fled, and Sunni shrines and orders were suppressed. This was coercion of Muslims into another form of Islam.[18] Majority
- Temple desecration in India. Richard Eaton counts eighty reasonably certain cases between 1192 and 1729, mostly of royal temples in newly conquered or rebellious territory, which he reads as political as well as religious acts; how to read them is argued in Hinduism §10.[19] Majority; Political
- In modern times the “Islamic State” forced conversions and enslaved Yazidi women; more than 120 Muslim scholars answered, in their open letter of September 2014, that it is forbidden in Islam “to force people to convert” (§13).[20] Consensus
These are real, and some were severe. They are also episodes, in particular regimes and periods, not the general pattern of how most of the conquered became Muslim. Majority
Where most Muslims live, Islam came without conquest
Today the largest Muslim populations are in Indonesia, Pakistan, India and Bangladesh.[21] Consensus Much of that map was drawn without Arab armies:
- Southeast Asia. Muslim traders were in the region long before any ruler converted. The earliest firm evidence of a Muslim ruler is a sultan’s gravestone of 1297 in Sumatra, and the Javanese courts converted in the fifteenth and sixteenth centuries, through trade, intermarriage and the conversion of port rulers, with Sufi teachers as interpreters.[22][23] Majority Michael Laffan cautions that the picture of a uniquely gentle conversion was itself partly shaped by later colonial scholarship and nationalism. Majority
- Bengal. Richard Eaton finds that conversion was heaviest not near the centres of Muslim power but on the agrarian frontier of the east, centuries after the conquest, as forest was cleared for rice.[24] Majority
- West Africa. Muslim traders crossed the Sahara from the eighth century; the rulers of Mali were Muslim by the thirteenth, and Islam spread first among rulers and merchants.[25] Majority
Debates
| View | Position | Representative scholars |
|---|---|---|
| Conquest, then slow conversion | The empire was won by war; the religion spread inside it over centuries, mostly without compulsion | Kennedy; Hoyland; Bulliet[2][9][13] |
| Longer Christian majorities | Conversion was even slower and the boundaries blurrier than Bulliet’s curve | Tannous[14] |
| Pressure, not force | The tax and status of non-Muslims were themselves a sustained pressure to convert | A long-standing argument, made in different forms by critics and historians |
Political The positions overlap; the disagreement is mostly over how to weigh pressure against choice.
Common misconceptions
- “The conquered were given a choice of Islam or death.” That was not the general rule for Christians, Jews or Zoroastrians, who could keep their religions on paying tribute. Majority
- “The Qur’an forbids all coercion, so it never happened.” Q 2:256 is real, and so are the episodes of coercion listed above. Consensus
- “The conquered lands became Muslim at once.” They kept non-Muslim majorities for generations, in places for centuries. Majority
- “Islam is an Arab religion spread by Arab armies.” Most Muslims today live in South and Southeast Asia, where Islam spread largely through trade, courts and teachers. Majority
References
- ^ Qur'an 2:256 — The Qur'an. 610–632 CE. Arabic. 'There is no compulsion in religion: true guidance has become distinct from error.' read the text
- ^ a b c Hugh Kennedy The Great Arab Conquests: How the Spread of Islam Changed the World We Live In. Weidenfeld & Nicolson, 2007. Narrative history of the conquests, region by region.
- ^ Thomas the Presbyter, Chronicle (British Library Add. MS 14,643) — Syriac Chronicle of 640. c. 640 CE (manuscript copied 724). Syriac. Records a battle on 4 February 634 between the Romans and 'the Arabs of Muhammad' twelve miles east of Gaza: the earliest datable text to name Muhammad. about
- ^ a b Robert G. Hoyland Seeing Islam as Others Saw It: A Survey and Evaluation of Christian, Jewish and Zoroastrian Writings on Early Islam. Darwin Press, 1997. The non-Muslim sources of the first Islamic century and a half, translated and discussed.
- ^ Hugh Kennedy The Prophet and the Age of the Caliphates. Longman, 1986. Standard political history of the Near East from Muhammad to the eleventh century.
- ^ Peter Jackson The Delhi Sultanate: A Political and Military History. Cambridge University Press, 1999. The standard political history of the Sultanate from its Ghurid origins.
- ^ Qur'an 9:29 — The Qur'an. 610–632 CE. Arabic. Fight the People of the Book who do not believe 'until they pay the tax (jizya) and agree to submit'. read the text
- ^ Milka Levy-Rubin Non-Muslims in the Early Islamic Empire: From Surrender to Coexistence. Cambridge University Press, 2011. Traces the Pact of Umar to conquest-era surrender treaties and Byzantine and Sasanian models.
- ^ a b c Robert G. Hoyland In God's Path: The Arab Conquests and the Creation of an Islamic Empire. Oxford University Press, 2015. The conquests as empire-building, set in the frontier politics of Byzantium and Persia.
- ^ John of Nikiu, Chronicle, chs. CXI–CXXI (trans. R. H. Charles, 1916) — John of Nikiu, Chronicle. c. 690 CE (Ethiopic version 1602). Ethiopic (Geʿez), from Arabic, from Greek or Coptic. A Coptic bishop's account of the Arab conquest of Egypt: the treaty for Alexandria, ʿAmr's taxes, his protection of churches, and early converts to Islam. read the text
- ^ Patricia Crone Slaves on Horses: The Evolution of the Islamic Polity. Cambridge University Press, 1980. The Umayyad polity, its tribal armies and the place of the mawālī.
- ^ H. A. R. Gibb The Fiscal Rescript of ʿUmar II. Arabica 2, 1955. ʿUmar II's rulings on converts and taxation.
- ^ a b c Richard W. Bulliet Conversion to Islam in the Medieval Period: An Essay in Quantitative History. Harvard University Press, 1979. The onomastic S-curve of conversion.
- ^ a b c Jack Tannous The Making of the Medieval Middle East: Religion, Society, and Simple Believers. Princeton University Press, 2018. Christian majorities for centuries after the conquests, and the blurred line between ordinary believers.
- ^ Hugh Kennedy Muslim Spain and Portugal: A Political History of al-Andalus. Longman, 1996. Standard political history from the conquest of 711 to the fall of Granada.
- ^ Joel L. Kraemer Maimonides: The Life and World of One of Civilization's Greatest Minds. Doubleday, 2008. Biography drawing heavily on the Geniza; discusses the evidence that his family outwardly converted under the Almohads.
- ^ Halil İnalcık The Ottoman Empire: The Classical Age, 1300–1600. Weidenfeld & Nicolson, 1973. The classic account of Ottoman institutions, including the learned hierarchy, kanun and the devşirme.
- ^ Andrew J. Newman Safavid Iran: Rebirth of a Persian Empire. I.B. Tauris, 2006. A political and religious history of the dynasty; sceptical of the scale of the ʿĀmilī clerical migration.
- ^ Richard M. Eaton "Temple Desecration and Indo-Muslim States". Journal of Islamic Studies 11, 2000. doi The survey behind the ~80 documented cases and the political-target pattern.
- ^ Open Letter to Dr. Ibrahim Awwad Al-Badri, alias Abu Bakr Al-Baghdadi (19 September 2014) — Open Letter to al-Baghdadi. 19 September 2014. Arabic and English. More than 120 Muslim scholars refute the Islamic State in 24 points, including the killing of innocents, forced conversion, slavery and the declaration of a caliphate without consensus. about
- ^ Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020: Muslim population change (9 June 2025) — Pew Research Center report. 2025. English. About 2 billion Muslims in 2020, 25.6% of the world's population, the fastest-growing major religious group of 2010–2020, mainly through youth and fertility. about
- ^ M. C. Ricklefs A History of Modern Indonesia since c. 1200. Palgrave Macmillan, 4th ed., 2008. Opens with the evidence for the Islamisation of the archipelago: gravestones, travellers and courts.
- ^ Michael Laffan The Makings of Indonesian Islam: Orientalism and the Narration of a Sufi Past. Princeton University Press, 2011. How colonial and nationalist scholarship shaped the story of Indonesia's Sufi conversion.
- ^ Richard M. Eaton The Rise of Islam and the Bengal Frontier, 1204–1760. University of California Press, 1993. doi Why conversion was heaviest far from the centres of Muslim power.
- ^ Nehemia Levtzion Ancient Ghana and Mali. Methuen, 1973. The West African empires and the coming of Islam to the Sahel.