Early Muslim Conquests: History and Legacy

The Prophet Muhammad ﷺ died on 8 June 632 CE in Medina, leaving behind a faith that had transformed Arabia in 23 years. Most observers at that moment might have expected the young Muslim community to consolidate quietly — to protect what they had built and settle the question of leadership. What happened instead was one of the most remarkable episodes in all of recorded history.

Within a century, Muslim armies had crossed three continents. Persia — an empire that had stood for over a thousand years — was absorbed within two decades. Egypt, the breadbasket of the ancient world, was taken with minimal bloodshed and its churches left untouched by order of the caliph. Spain was entered in 711 CE. The Indus Valley came under Muslim governance by 712 CE. No military expansion in the ancient or medieval world moved so far, so fast.

Understanding the early Muslim conquests is not just history. It is theology, justice, and a lived example of what the Quran calls bearing witness to truth before all of humanity.

What Were the Early Muslim Conquests?

The early Muslim conquests were the rapid military campaigns launched by the Rashidun caliphate between 632 and 661 CE, and continued by the Umayyad dynasty to 750 CE, through which Muslim governance extended from the Arabian Peninsula across the Levant, Persia, Egypt, North Africa, Spain, and the Indus Valley. Beginning immediately after the death of the Prophet ﷺ, these campaigns dismantled two ancient superpowers — the Byzantine Empire in the west and the Sassanid Persian Empire in the east — within the lifetimes of the Prophet's companions.

The Rashidun Caliphate: The Four Phases

The first four caliphs — Abu Bakr, Umar ibn al-Khattab, Uthman ibn Affan, and Ali ibn Abi Talib — governed what Muslims call the Rashidun ("Rightly Guided") period. Each phase had its own character.

Phase 1: Abu Bakr (632–634 CE) — Holding the Community Together

When the Prophet ﷺ died, tribal leaders across Arabia saw an opportunity to withdraw their allegiance to Medina. Abu Bakr immediately recognized that the community's survival required unity. The Ridda Wars — campaigns against apostasy and rebellion — reunified the peninsula within a year.

What is striking about Abu Bakr's campaigns is their restraint. His commanders were explicitly instructed not to harm those who had not taken up arms, not to cut down trees, not to destroy crops, and not to harm women, children, or the elderly. These were not ordinary military orders for the 7th century.

Phase 2: Umar ibn al-Khattab (634–644 CE) — The Great Expansion

Umar's decade as caliph changed the world. His armies faced two ancient superpowers simultaneously and defeated both. In 636 CE alone, two of the most consequential battles in history occurred:

The Battle of Yarmouk (August 636 CE) — Muslim forces under the command of Khalid ibn al-Walid defeated the Byzantine army and secured Syria and Palestine. Caliph Umar himself traveled to Jerusalem in 638 CE to accept its surrender. In a moment historians still cite, Umar walked through the city on foot rather than on horseback so as not to dishonor the holy city. He entered the Church of the Holy Sepulchre but refused to pray there, explaining that he feared future Muslims might use it as a pretext to turn it into a mosque. He prayed on the steps outside instead.

The Battle of al-Qadisiyyah (636 CE) — Muslim forces under Saad ibn Abi Waqqas broke the Sassanid army. The ancient Persian capital Ctesiphon fell within the year, and the Persian heartland was open. Egypt came under Muslim governance by 642 CE.

Phases 3 and 4: Uthman and Ali (644–661 CE) — Consolidation

Under Uthman ibn Affan, the conquest of Persia was completed by 651 CE, and Muslim forces reached Cyprus. Under Ali ibn Abi Talib, the caliphate managed internal political tensions — the First Fitna — more than external expansion.

The Umayyad Continuation (661–750 CE)

The Umayyad caliphate extended Muslim governance to Spain in 711 CE under Tariq ibn Ziyad, whose name is preserved in the landmark he crossed — Jabal Tariq (Gibraltar). In the east, Muslim armies reached the Indus Valley by 712 CE. The westward advance into France was halted at the Battle of Tours in 732 CE.

Early Muslim Conquests at a Glance

Why Did the Early Conquests Succeed So Rapidly?

Historians have offered many explanations, and they are not mutually exclusive.

The exhaustion of the superpowers. The Byzantine and Sassanid empires had waged a catastrophic series of wars against each other from 603 to 628 CE — just four years before the conquests began. Both were militarily depleted, financially drained, and politically unstable. The Arab armies arrived against opponents who had already bled each other almost to collapse.

The character of Muslim governance. Many subject populations under Byzantine rule had been taxed heavily and — in the case of Coptic Christians in Egypt — subjected to theological persecution by Constantinople. Muslim governance offered lower taxes, religious tolerance under the dhimma (ذِمَّة) covenant, and a system of governance grounded in the Quran's demand for justice.

The Quran grounded this standard in an absolute obligation:

يَا أَيُّهَا الَّذِينَ آمَنُوا كُونُوا قَوَّامِينَ بِالْقِسْطِ

"O you who believe, be persistently standing firmly for justice." — (Surah An-Nisa, 4:135)

Motivated soldiers and disciplined leadership. Muslim commanders like Khalid ibn al-Walid, Amr ibn al-As, and Saad ibn Abi Waqqas were products of the Prophet's ﷺ direct mentorship and the Quranic ethics they had internalized. The Prophet ﷺ himself had said: "Convey from me, even if it is one verse" (Sahih al-Bukhari 3461). Carrying the message, including through governance, was understood as a sacred responsibility.

How Did Muslim Rulers Govern Conquered Peoples?

This is perhaps the most important — and most misunderstood — aspect of the early conquests.

The foundational Quranic principle was clear:

لَا إِكْرَاهَ فِي الدِّينِ

"There is no compulsion in religion." — (Surah Al-Baqarah, 2:256)

In practice, this meant that conquered populations were not forced to convert. They were presented with a choice: enter Islam voluntarily, accept protected status under the dhimma agreement and pay jizya (a poll tax that replaced the zakat Muslims paid), or negotiate a treaty with the new authorities.

DeenBack's account of the first caliphs of Islam traces how this governance model shaped the caliphate's relationship with diverse populations — and why many communities actively welcomed Muslim rule rather than merely enduring it.

Umar ibn al-Khattab's instructions before the conquest of Syria set the standard:

• Do not kill women, children, or the elderly
• Do not destroy churches, monasteries, or synagogues
• Do not cut down trees or burn crops
• Fulfill whatever agreements you make

Jerusalem's Patriarch Sophronius surrendered the city to Umar in person — precisely because he had heard of Umar's reputation for keeping his word. Egypt's Coptic Christian community, long persecuted by Byzantine authorities over theological disputes, frequently cooperated with the Muslim advance.

Demimanifest's reflection on faith and Islamic historical roots explores how these Quranic values — transparency, accountability, protection of the vulnerable — shaped the moral architecture of the early caliphate and why it produced a form of governance that many communities genuinely preferred.

What Does This History Mean for Muslims Today?

The early Muslim conquests are sometimes presented — by critics and by some Muslims alike — as primarily a story of military power. The historical record tells a more nuanced story.

The Quran itself frames the Muslim community not as conquerors but as witnesses:

وَكَذَٰلِكَ جَعَلْنَاكُمْ أُمَّةً وَسَطًا لِّتَكُونُوا شُهَدَاءَ عَلَى النَّاسِ

"And thus We have made you a middle community so that you may be witnesses over the people." — (Surah Al-Baqarah, 2:143)

The companion Rabi ibn Amir, sent to negotiate with the Persian general Rustam before al-Qadisiyyah, gave what many scholars regard as the defining statement of purpose. When Rustam asked why they had come, he replied: "Allah has sent us to lead people from the worship of creation to the worship of the Creator, from the constriction of this world to its expanse, and from the injustice of other religions to the justice of Islam."

This is the Islamic understanding: the conquests were not an end in themselves. They were the vehicle through which governance rooted in divine justice was extended to people who had never experienced it. The scholars, trade routes, and institutions that followed — the hospitals, libraries, and centers of learning built across the conquered lands — were the point.

For Muslims today, this history offers a reminder that Islam has always been a civilizational project, not just a personal practice. Understanding it through the lens of the Quran and the companions' example is far more illuminating than viewing it through a narrow political lens.

For more on how Islam spread beyond the conquests, see our related guides on the expansion of Islam and how Islam spread through trade and scholarship. The Arab conquest article goes deeper into the campaigns in Syria and Iraq, while our piece on the early Muslim community provides context for who these soldiers and caliphs actually were. The conquest of Mecca — the spiritual precursor to all later expansion — is also worth reading alongside this history.

Common Questions About the Early Muslim Conquests

Why do some people say the conquests spread Islam by the sword?

This critique is partly rooted in historical truth — there were genuine military campaigns — and partly in selective reading. The evidence consistently shows that mass forced conversion was not practiced. Egypt remained majority Christian for centuries after its conquest. Persia retained Zoroastrian communities for generations. The Quran's prohibition of compulsion was taken seriously.

What happened to non-Muslims after the conquests?

They became dhimmis (people of the covenant), entitled to state protection, the right to practice their faith, and access to their own courts for internal disputes. In exchange, they paid the jizya and could not hold certain military or senior administrative positions. This system was imperfect by modern standards but was far more tolerant than the religious policies of most contemporaneous Christian or Zoroastrian states.

Were the conquests approved by the Quran?

The Quran does permit fighting to remove oppression and defend the right to worship: "And fight them until there is no fitnah and the religion is entirely for Allah" (Surah Al-Anfal, 8:39). However, it also commands strict proportionality and absolutely forbids aggression: "Fight in the way of Allah those who fight you, but do not transgress. Indeed, Allah does not like transgressors" (Surah Al-Baqarah, 2:190).

Islamic law, developed by scholars over subsequent centuries, drew on both of these principles to build a sophisticated framework for when force was and was not permissible.

Moving Forward with This Knowledge

The early Muslim conquests left behind a civilization — not just a territory. The scholars, poets, physicians, and mathematicians who built the Islamic Golden Age did so in the cities and institutions established in the wake of these campaigns. Baghdad, Cairo, Cordoba, and Samarkand became world centers of knowledge and culture precisely because Islamic governance, at its best, valued and protected intellectual life.

As a Muslim today, you are part of that inheritance. The ummah that stretches from Indonesia to Senegal, from Bosnia to Brazil, did not emerge because of military force alone. It emerged because the message of Islam — grounded in justice, dignity, and the direct relationship between the human soul and Allah — spoke to something universal.