14.1 Expansion of Islam

The New Phase after Hudaybiyyah

By the time the Prophet ﷺ entered the final years of his life, the Seerah had moved from a phase of survival and defense to a phase of confident expansion. The Treaty of Hudaybiyyah had calmed open conflict with Quraysh, and the people of Arabia were finally able to hear the message of Islam without the same level of fear or pressure. Allah describes this turning point in very clear words:

إِنَّا فَتَحْنَا لَكَ فَتْحًا مُّبِينًا
“Indeed, We have given you a clear conquest.”
(Surah Al-Fath 48:1)

Many scholars explained that this “clear conquest” refers first to Hudaybiyyah, which opened the door for Islam to spread peacefully. Within a few short years after this treaty, Islam expanded across Arabia, and its light reached beyond the peninsula, to the courts of the greatest empires of the time. In this chapter we will look at three main aspects of this expansion: the letters sent by the Prophet ﷺ to rulers, the delegations that came to Madinah, and how Islam spread across Arabia before his passing.

Letters to Kings and Rulers

When the Prophet ﷺ felt secure enough inside Arabia, he began to address the wider world. In the sixth year after Hijrah, after Hudaybiyyah, he ﷺ sent written messages to several rulers inviting them to Islam. This was not a political game. It was a sincere call to faith, based on his responsibility as the final Messenger to all humanity.

Allah had commanded:

قُلْ يَا أَيُّهَا النَّاسُ إِنِّي رَسُولُ اللَّهِ إِلَيْكُمْ جَمِيعًا
“Say, O mankind, indeed I am the Messenger of Allah to you all.”
(Surah Al-A‘raf 7:158)

The letters were a practical expression of this verse. They showed that Islam was not only for one tribe or one land, but for every nation.

The Form and Style of the Letters

The letters shared some common features. They were brief, clear, and respectful. They began in the name of Allah, and they identified him ﷺ as the Messenger of Allah. In general, his letters included the testimony of faith and a warning that accepting or rejecting the message would have consequences.

One famous example is the letter to Heraclius, the Roman emperor. It began:

«بِسْمِ اللَّهِ الرَّحْمَنِ الرَّحِيمِ
مِنْ مُحَمَّدٍ عَبْدِ اللَّهِ وَرَسُولِهِ، إِلَى هِرَقْلَ عَظِيمِ الرُّومِ، سَلَامٌ عَلَى مَنِ اتَّبَعَ الْهُدَى، أَمَّا بَعْدُ، فَإِنِّي أَدْعُوكَ بِدِعَايَةِ الْإِسْلَامِ، أَسْلِمْ تَسْلَمْ، يُؤْتِكَ اللَّهُ أَجْرَكَ مَرَّتَيْنِ، فَإِنْ تَوَلَّيْتَ فَإِنَّ عَلَيْكَ إِثْمَ الأَرِيسِيِّينَ…»
“In the name of Allah, the Most Merciful, the Most Compassionate.
From Muhammad, the slave of Allah and His Messenger, to Heraclius, the great one of the Romans. Peace be upon whoever follows the guidance.
To proceed, I invite you with the call of Islam. Accept Islam and you will be safe. Allah will give you your reward twice. If you turn away, then upon you is the sin of your people.”
(Sahih al-Bukhari)

This style shows humility, clarity, and firmness. The Prophet ﷺ identified himself as a servant, not a king. At the same time, he spoke with the authority of a Messenger.

Envoys as Examples of Muslim Character

The men who carried these letters were not ordinary messengers. They were chosen for their knowledge, faith, and good manners. Through them, foreign courts saw a living example of Islamic character.

To the Negus of Abyssinia, he ﷺ sent ‘Amr ibn Umayyah ad-Damri. To the ruler of Egypt, al-Muqawqis, he sent Hatib ibn Abi Balta‘ah. To the Persian ruler Kisra (Khosrow), he sent ‘Abdullah ibn Hudhafah as-Sahmi. Each envoy had to face a different type of reaction. Some rulers honored the messengers, others showed arrogance and mockery. The envoys showed patience, dignity, and trust in Allah in all situations.

The Prophet ﷺ had taught his companions:

«إِنَّكَ تَأْتِي قَوْمًا مِنْ أَهْلِ الْكِتَابِ…»
“You are going to a people of the Book…”
(Sahih al-Bukhari)

He spoke these words to Mu‘adh ibn Jabal when sending him to Yemen. He instructed him to start by calling them to the testimony of faith, then to prayer, then to zakah. This graded method of da‘wah, beginning with the foundation, shaped how his envoys approached people both inside and outside Arabia.

Responses to the Letters

The responses were varied, and each response had an impact.

Heraclius did not accept Islam, but he took the message very seriously. He examined the signs, asked detailed questions about the Prophet ﷺ through Abu Sufyan, and recognized many marks of true prophethood. Abu Sufyan, still a non-Muslim at that time, later said that this was the moment he became certain that the Prophet ﷺ would eventually prevail.

Al-Muqawqis of Egypt also did not accept Islam, but he treated the envoy with respect. He sent gifts, including Mariyah, who later bore the Prophet ﷺ a son, Ibrahim. This showed at least an outward recognition of the Prophet’s status, even if he did not embrace the faith.

Kisra, the Persian emperor, responded with open arrogance. When the letter reached him, he tore it apart. The Prophet ﷺ replied with a brief but serious statement:

«مَزَّقَ اللَّهُ مُلْكَهُ»
“May Allah tear his kingdom apart.”
(Musnad Ahmad)

Soon after, his power began to break from within. His own son killed him, and within a few decades, the Persian empire collapsed completely in front of the Muslims. The tearing of the letter became a symbol of how rejecting truth with pride leads to destruction.

Another example is the letter to the rulers of Bahrain and to other local chiefs around the Gulf and eastern Arabia. Some of them accepted Islam, some agreed to peaceful terms under Muslim rule while keeping their Christian or Jewish faith. Their acceptance opened whole regions to Islam without battle.

These letters and the reactions to them showed that the message of Islam had now entered the stage of international awareness. Even when rulers rejected it, they could no longer ignore it. The Prophet ﷺ was recognized as a real leader, not only a preacher inside a small town.

Delegations to Madinah

As Islam spread, tribes and communities began to send their own delegations to meet the Prophet ﷺ. These visits reached their peak in what historians call “The Year of Delegations,” which occurred near the end of his life, around the ninth year after Hijrah.

Allah describes the rising tide of people entering Islam:

إِذَا جَاء نَصْرُ اللَّهِ وَالْفَتْحُ
وَرَأَيْتَ النَّاسَ يَدْخُلُونَ فِي دِينِ اللَّهِ أَفْوَاجًا
“When the help of Allah and the victory come,
and you see the people entering into the religion of Allah in crowds.”
(Surah An-Nasr 110:1–2)

The delegations were these “crowds” arriving in person at Madinah. Their visits were more than formal meetings. They were a chance to learn the basics of Islam, to ask questions, to form treaties, and to watch how the Muslims lived on a daily basis.

Reasons for Sending Delegations

Tribes sent delegations for several reasons. Some had heard of the Prophet’s victories and the fall of old enemies, and they wanted to understand his message before making a decision. Others saw that waiting on the sidelines was no longer wise. They preferred to enter Islam while they still had the choice, rather than face conflict later. Some were drawn by genuine belief, after hearing the Quran recited by traders or travelers.

The delegations also reflected a shift in power. Before, tribes would go to the great courts of Rome or Persia. Now they traveled to Madinah, a small city that had become the center of a rising moral and political force. This alone shows how deeply the Prophet ﷺ had transformed Arabia.

How the Prophet ﷺ Received Delegations

The Prophet ﷺ welcomed delegations with generosity and honor. He would accommodate them in the mosque or in specific houses, provide food, and give them time to observe him and ask questions. He treated guests with respect, even if they arrived with doubt or arrogance.

The Quran describes the believers as people of consultation:

وَأَمْرُهُمْ شُورَىٰ بَيْنَهُمْ
“And their affairs are (conducted) by mutual consultation among them.”
(Surah Ash-Shura 42:38)

Although this verse speaks generally, the Prophet ﷺ showed this spirit when dealing with tribes. He listened to their conditions, he considered their situations, and he gave rulings or agreements that took their realities into account, so long as they did not contradict the clear laws of Islam.

Many delegations requested teachers to return with them. The Prophet ﷺ often sent companions who excelled in Quran, fiqh, and good character. Through them, whole tribes learned how to pray, pay zakah, solve disputes, and build their communities on an Islamic foundation.

Famous Delegations and Their Features

Among the many delegations, some became well known because of specific stories or lessons.

One of the most famous is the delegation of ‘Abd al-Qays, from the eastern region of Arabia. The Prophet ﷺ praised them for coming to him eagerly and asked them about their people. He then summarized for them the core duties of Islam. In one narration, he said:

«آمُرُكُمْ بِأَرْبَعٍ، وَأَنْهَاكُمْ عَنْ أَرْبَعٍ… تُؤْمِنُوا بِاللَّهِ… وَإِقَامِ الصَّلَاةِ، وَإِيتَاءِ الزَّكَاةِ، وَأَنْ تُؤَدُّوا خُمُسَ مَا غَنِمْتُمْ…»
“I command you with four things and I forbid you from four things… that you believe in Allah… and that you establish the prayer, give the zakah, and give the fifth of what you gain (from war)…”
(Sahih al-Bukhari, Sahih Muslim)

With this, he gave them a simple framework to build their new Islamic life.

Another well-known case is the Christians of Najran, from the south of Arabia. They came as a delegation to debate matters of belief about ‘Isa عليه السلام. The Prophet ﷺ listened to them and recited verses of the Quran that describe the truth about Jesus, such as:

إِنَّ مَثَلَ عِيسَىٰ عِندَ اللَّهِ كَمَثَلِ آدَمَ ۖ خَلَقَهُ مِن تُرَابٍ ثُمَّ قَالَ لَهُ كُن فَيَكُونُ
“Indeed, the example of Jesus to Allah is like that of Adam. He created him from dust, then He said to him, ‘Be,’ and he was.”
(Surah Al ‘Imran 3:59)

Although they did not accept Islam, they agreed to live under Muslim protection and pay jizyah, a form of tax in place of military service and zakah. This set a practical example of how non-Muslim communities could live under an Islamic government with rights and security.

There were also delegations from tribes that had previously fought the Muslims. Some came to make peace, others came after seeing that resistance was no longer possible. The Prophet ﷺ accepted their pledges and often forgave past hostility, as long as they accepted the new reality and did not continue aggression. In this way, his mercy turned former enemies into brothers in faith.

Spread Across Arabia

By the end of the Prophet’s life, the map of Arabia had changed completely. Islam was no longer limited to Makkah and Madinah with a few scattered supporters. It had become the main religion in most of the peninsula. This transformation was not a simple political takeover. It was a deep change in belief, worship, and social life.

From Local Message to National Reality

At the start of the mission in Makkah, the Muslims were few and weak. By the time of the Hijrah, they had a city state in Madinah. After Badr, Uhud, and Khandaq, they had secured their survival. After Hudaybiyyah and the Conquest of Makkah, they became the central authority in Western Arabia.

Then came a sequence of key events. The Conquest of Makkah removed the main symbol of old pagan leadership. Idols were destroyed in the Ka‘bah, and the Prophet ﷺ recited:

وَقُلْ جَاءَ الْحَقُّ وَزَهَقَ الْبَاطِلُ ۚ إِنَّ الْبَاطِلَ كَانَ زَهُوقًا
“And say, ‘Truth has come, and falsehood has vanished. Indeed, falsehood is ever bound to vanish.’”
(Surah Al-Isra’ 17:81)

After this, many tribes that had been watching from a distance no longer had reasons to hesitate. They saw that Quraysh, the custodians of the Ka‘bah, had themselves entered Islam. Pride and fear both began to dissolve.

The battles of Hunayn and Ta’if then broke the resistance of major tribes in the central and western regions. The expedition to Tabuk showed that the Muslims were now confident enough to face the Roman power at its border. Even though no major battle occurred there, the very act of marching north sent a clear message: the age of fear was over.

Islam in Different Regions of Arabia

Islam spread across Arabia in different ways in different places. In some areas, whole tribes embraced Islam after clear signs and thoughtful discussion. In other regions, smaller groups accepted it first, then slowly influenced their families and neighbors.

In Yemen, Islam reached people through letters, envoys like Mu‘adh ibn Jabal and Abu Musa al-Ash‘ari, and sometimes through local rulers who accepted Islam and encouraged their people to follow. The Prophet ﷺ tailored his instructions to their context, guiding his envoys to teach gradually and fairly.

He said to Mu‘adh when sending him to Yemen:

«إِنَّكَ تَأْتِي قَوْمًا أَهْلَ كِتَابٍ، فَلْيَكُنْ أَوَّلَ مَا تَدْعُوهُمْ إِلَيْهِ شَهَادَةُ أَنْ لَا إِلَهَ إِلَّا اللَّهُ، وَأَنِّي رَسُولُ اللَّهِ، فَإِنْ هُمْ أَطَاعُوا لِذَلِكَ، فَأَعْلِمْهُمْ أَنَّ اللَّهَ قَدْ فَرَضَ عَلَيْهِمْ خَمْسَ صَلَوَاتٍ فِي كُلِّ يَوْمٍ وَلَيْلَةٍ…»
“You are going to a people of the Book. Let the first thing you call them to be the testimony that none has the right to be worshipped but Allah and that I am the Messenger of Allah. If they obey you in that, then inform them that Allah has obligated upon them five prayers in every day and night…”
(Sahih al-Bukhari, Sahih Muslim)

This guidance shows how the spread of Islam was orderly and based on priorities. It was not just about names or labels. It was about establishing true belief, then regular worship, then social duties like zakah.

In the eastern regions, such as Bahrain and the surrounding areas, many people accepted Islam through correspondence and local teachers. Some Christian and Jewish communities remained upon their faith, but recognized the authority of the Muslim state and lived under its protection. This created a diverse society under a shared political and legal framework.

From Idols to Tawhid

One of the clearest signs of expansion was the removal of idols across Arabia. After the Conquest of Makkah, the Prophet ﷺ sent companions to demolish famous shrines that had drawn pilgrims for generations. Among these were al-Lat in Ta’if, al-‘Uzza near Makkah, and Manat on the coast. Each represented a center of old belief and tribal pride.

The fall of these idols was not only a physical act. It symbolized the end of a long history of shirk and the beginning of a new era of tawhid. The people of Arabia now directed their prayers to Allah alone, faced a single qiblah, and performed one Hajj under a unified ritual.

The Prophet ﷺ taught them:

«مَنْ قَالَ لَا إِلَهَ إِلَّا اللَّهُ، وَكَفَرَ بِمَا يُعْبَدُ مِنْ دُونِ اللَّهِ، حَرُمَ مَالُهُ وَدَمُهُ، وَحِسَابُهُ عَلَى اللَّهِ»
“Whoever says, ‘There is no god but Allah’ and rejects whatever is worshipped besides Allah, his wealth and his blood become inviolable, and his account is with Allah.”
(Sahih Muslim)

The expansion of Islam across Arabia therefore meant not only increased numbers, but a complete shift in what people worshipped, how they understood life and death, and how they organized their society.

Unity after Tribal Rivalries

Pre-Islamic Arabia was divided by endless tribal conflicts. Wars such as the long “Fijar” wars and other feuds had left deep wounds. Each tribe had its own idols, its own pride, and its own grudges. Through Islam, these barriers began to fall.

The Prophet ﷺ taught that the real bond was no longer tribal blood, but faith. Allah revealed:

إِنَّمَا الْمُؤْمِنُونَ إِخْوَةٌ
“The believers are but brothers.”
(Surah Al-Hujurat 49:10)

As Islam expanded, this verse turned into a social reality. Men from tribes that once killed each other now stood shoulder to shoulder in prayer and on the battlefield. They shared food, intermarried, and supported each other in hardship. A new identity was rising, the identity of the Ummah.

Preparing for a Wider Mission

By the time the Prophet ﷺ performed his Farewell Pilgrimage, the expansion of Islam in Arabia was almost complete. The Hajj of that year gathered tens of thousands of Muslims. They listened as he ﷺ delivered his famous sermon, outlining the core principles of justice, the sanctity of life and property, and the equality of all people before Allah.

Although the details of Hajj al-Wada‘ belong to another chapter, it is important here to see its link with expansion. The Farewell Pilgrimage showed the world a new Arabia, united behind one Prophet and one Book. It closed the chapter of scattered tribes and opened the chapter of a community ready to carry the message beyond its borders.

Islam’s expansion in the final years of the Prophet’s life therefore was not simply a historical fact. It was the fulfillment of a divine promise, and the preparation of an Ummah that would soon carry the Quran from the deserts of Arabia to every corner of the earth.