How Islam spread: 610 to 1924

Between 632 and 750 the armies of three successive caliphates took Persia, Syria, Palestine, Egypt, North Africa, Spain, Sindh and Transoxiana. Roughly ten million square kilometres in four generations. No empire before or since expanded that fast, and the mechanism was not preaching.

The sentence that gets taught instead is “Islam spread through trade.” That sentence is true of Indonesia, Malaysia, coastal East Africa and much of the Sahel. It is not true of the countries where most Muslims live, and it is not what happened to the civilisations that were there first.

Both halves of the map belong on this page. Presenting only the second half is the propaganda. Presenting only the first half would be the mirror image of it, and would be wrong.

The two mechanisms, and where each one operated

	The core	The rim
Where	Arabia, Iraq, Iran, Syria, Palestine, Egypt, North Africa, Spain, Sindh, Central Asia, Anatolia, the Balkans	Indonesia, Malaysia, Brunei, coastal East Africa, much of the Sahel
When	622 to 750, then Anatolia 1071 to 1453	8th to 16th centuries
How	Conquest by field army, tribute imposed on the survivors, conversion over generations under legal and fiscal pressure	Merchants, Sufi orders, dynastic marriage, rulers converting and their subjects following
Result	Zoroastrian Persia, Christian North Africa, Christian Egypt, Christian Anatolia, Buddhist Central Asia: gone or reduced to remnants	Hindu-Buddhist Java and Sumatra converted without a conquering army

Indonesia is the largest Muslim country on earth and it was not conquered. That is the strongest fact the other side has, it is real, and the scholarship is not seriously divided about it: Islam arrived in the archipelago with Gujarati and Persian traders from the thirteenth century, spread through Sufi teachers and the conversion of local rulers, and the first sultanate at Samudra Pasai grew out of a trading port rather than a garrison.

Hold that next to Persia. In 633 the Sassanid Empire was four centuries old and Zoroastrian. By 651 it did not exist. Today there are roughly twenty thousand Zoroastrians left in Iran.

Same religion. Two completely different processes. The word “spread” is doing the work of concealing which one happened where.

The phases

Muhammad and Arabia, 622 to 632. Medina, the campaigns against Mecca and the Arabian tribes, the expulsion and destruction of the Jewish tribes of the Hijaz.
The Ridda wars, 632 to 633. Abu Bakr’s campaign against the tribes that tried to leave after Muhammad’s death. Islam’s first war was fought against apostates, and it established the principle that leaving is not permitted.
The Rashidun conquests, 633 to 661. Persia, Syria, Palestine, Egypt, Libya. The two decisive battles are Yarmouk against the Byzantines in 636 and Qadisiyyah against the Sassanids in the same year.
The Umayyad expansion, 661 to 750. The Maghreb to the Atlantic, Spain from 711, Sindh from 711, Transoxiana under Qutayba ibn Muslim from 705. Stopped in France in 732 and outside Constantinople in 718.
The Abbasid consolidation, 750 to 1258. Less new conquest, more institutionalisation: the legal architecture of dhimma, the slave trades, the Turkic slave-soldier system that eventually took the caliphate over.
The Turkic and Mongol-successor conquests, 1071 to 1526. Anatolia after Manzikert, India under the Ghaznavids, the Delhi Sultanate, the Mughals.
The Ottoman centuries, 1354 to 1924. The Balkans, Constantinople in 1453, the devshirme, and the last caliphate, abolished by Atatürk on 3 March 1924.
The African jihad states, 1670 to 1903. Not medieval at all: Usman dan Fodio’s jihad founded the Sokoto Caliphate in 1804, which ran on slave raiding until the British ended it in 1903.

What this section holds

The caliphates, one by one: Rashidun, Umayyad, Abbasid, Fatimid, Almohad, Ottoman, Sokoto, what each conquered and what it did with what it took.
Every Muslim-majority country, and how it got that way: the ledger. What was there before, the year it changed, the army or the merchant fleet that changed it.
What Wikipedia did to the conquest articles: our own audit of the cluster. Conquest became expansion, Muslim became Umayyad, and “under Muslim rule” became “governed by Islamic law.”

Why a Jewish site keeps this record

Because we are in it. The Jewish tribes of the Hijaz are the first entry in phase one, Babylonian Jewry ended in the Farhud and the expulsions, and the 850,000 Jews driven out of Arab and Muslim countries after 1948 are the last chapter of a legal relationship that began in the seventh century. You cannot explain the second without the first.

And because the argument made against Israel every day is that a people cannot claim land it took by force in living memory. That argument is made from countries whose own borders were drawn by cavalry in the 640s, whose majority religion arrived in a supply train, and whose indigenous populations are the remnant communities in the table above.

Sources

Every page in this section

Egypt: how a Christian country became a Muslim one Conquered in 642, Muslim-majority only by the 14th century. A peer-reviewed study of the tax records shows what did it: the jizya, applied for seven hundred years.
Iran: the empire that was Zoroastrian for a thousand years The Sassanid state was four centuries old in 633 and did not exist by 651. Roughly twenty thousand Zoroastrians remain in Iran, in the country that invented the religion.
Mauritania: the last country on earth to abolish slavery Islamized by the Almoravids in the 11th century. Slavery abolished in 1981, criminalized in 2007, and the descendants of the enslaved are about 40% of the population.
Nubia: the Christian kingdom that paid its tribute in slaves Christian Nubia stopped the Arab advance in 652 and survived seven hundred years. The treaty that bought that survival required 360 slaves a year.
Turkey: from Manzikert to the end of the caliphate Anatolia was Greek and Armenian Christian for a thousand years. Christians were a fifth of the population in 1914 and are under one per cent today.