When Was Islam Founded? The Complete Timeline

Questions about when Islam started come up often — in school, in historical research, in news coverage, and in conversations between Muslims and their non-Muslim friends. The question seems straightforward, but the answer opens up one of the most remarkable stories in human history.

Unlike some ancient religions whose founding is shrouded in uncertainty, Islam has a remarkably specific starting point: a night in the month of Ramadan in 610 CE, in a cave on the outskirts of Mecca. From that single moment, a 23-year prophetic mission began that would transform not just Arabia but the course of world civilization.

Understanding when Islam was founded also helps you understand why Muslims revere the Quran the way they do, why the early Companions hold such a central place in scholarship and tradition, and why the Islamic calendar begins not in 610 CE but in 622 CE — a detail that carries deep meaning.

When Was Islam Founded?

Islam was founded in 610 CE when the Prophet Muhammad ﷺ, then 40 years old, received his first revelation from the angel Jibril (Gabriel) in the Cave of Hira near Mecca. The first words revealed were from Surah Al-Alaq (96:1): Iqra bismi rabbika alladhi khalaq — "Read in the name of your Lord who created." This began a 23-year prophetic mission that concluded in 632 CE with the final sermon and the completion of the Quran.

What Really Happened in the Cave of Hira in 610 CE?

The Prophet Muhammad ﷺ was known among his people as Al-Amin (الأمين) — the trustworthy one — long before he received revelation. He was known for honesty, generosity, and deep reflection, and he spent periods of solitary retreat in the Cave of Hira on the mountain of Jabal al-Nur, outside Mecca.

During one such retreat, in the month of Ramadan, the angel Jibril appeared. What followed is recorded in the earliest and most authenticated hadith collection:

The angel came to him and said: "Read!" The Prophet replied: "I do not know how to read." The angel embraced him tightly, then released him and said again: "Read!" This happened three times, after which Jibril recited the first verses. — (Sahih al-Bukhari 3)

The first five verses of the Quran were then revealed:

اقْرَأْ بِاسْمِ رَبِّكَ الَّذِي خَلَقَ ۝ خَلَقَ الْإِنسَانَ مِنْ عَلَقٍ ۝ اقْرَأْ وَرَبُّكَ الْأَكْرَمُ ۝ الَّذِي عَلَّمَ بِالْقَلَمِ ۝ عَلَّمَ الْإِنسَانَ مَا لَمْ يَعْلَمْ

"Read in the name of your Lord who created — created man from a clinging substance. Read, and your Lord is the most Generous — who taught by the pen — taught man that which he knew not." (Surah Al-Alaq, 96:1-5)

Shaken and uncertain, the Prophet returned to his wife Khadijah RA, who wrapped him in a cloak and reassured him. She later took him to her cousin Waraqah ibn Nawfal — an elderly Christian scholar who had studied the earlier scriptures — who confirmed that what the Prophet had received was the same angel who had brought revelation to Musa (Moses). This too is recorded in Sahih al-Bukhari 3.

For the full context of this sacred place and its role in early Islam, our guide to the Cave of Hira explores its significance in detail.

Key Dates in the Founding and Early Spread of Islam

Was Islam "Founded" in 610 CE, or Is It Older Than That?

This is a question Islamic scholars often raise — and it is worth understanding. Muslims do not believe Islam was created from scratch by Muhammad ﷺ in the same way a new philosophy might be invented by one thinker.

The Quran teaches that Islam — meaning submission to Allah — is the original religion of all humanity, sent through a long chain of prophets:

إِنَّ الدِّينَ عِندَ اللَّهِ الْإِسْلَامُ

"Indeed, the religion in the sight of Allah is Islam." (Surah Al-Imran, 3:19)

The Prophet Ibrahim (Abraham, peace be upon him) declared his own submission: "I have submitted myself to the Lord of the worlds" (Surah Al-Baqarah, 2:131). Musa, Isa, and all the prophets are considered Muslims in the Quranic sense — people who fully submitted to Allah.

What 610 CE marks, then, is the beginning of the final and complete revelation — the Quran — and the prophethood of Muhammad ﷺ as the Seal of all Prophets (Khatam al-Nabiyyin). This is why Muslims say "the religion of all the prophets is Islam," while pointing to 610 CE as the founding of the community and scripture we know today.

For the theological foundation behind this belief, see our guide on what is Islam.

How Old Is Islam, and How Many People Follow It Today?

As of 2026 CE (1447 AH), Islam is approximately 1,416 years old from the first revelation, or 1,404 years old from the Hijra that began the Islamic calendar.

Islam is currently the second largest religion in the world, with an estimated 1.9 billion adherents — approximately 24% of the global population. It is also the fastest growing major religion by absolute numbers.

The countries with the largest Muslim populations are not in Arabia: they are Indonesia (231 million), Pakistan (212 million), Bangladesh (153 million), and Nigeria (99 million). This global diversity reflects the universality of the Islamic message — a faith that crossed language, ethnicity, and geography within its first century.

Why Did the Islamic Calendar Start in 622 CE, Not 610 CE?

The Islamic calendar begins with the year of the Hijra — the migration of the Prophet ﷺ and his companions from Mecca to Medina — not with the year of the first revelation. This was a deliberate choice made by the Caliph Umar ibn al-Khattab RA in consultation with the Companions.

The reason: 622 CE marked the birth of the Muslim ummah as a community, not just a spiritual movement. In Medina, the Prophet ﷺ established:

• The first mosque (Masjid al-Nabawi)
• A written charter governing relations between Muslims and non-Muslim tribes (the Constitution of Medina)
• The full system of prayer, zakat, and community life

The Hijra was therefore the moment Islam took on its complete social and legal form — which is why it begins the calendar. Our guide on the migration to Medina covers this pivotal event in full.

Where Did Islam Spread After 610 CE?

The spread of Islam after its founding is among the most dramatic stories in world history. Within the Prophet's own lifetime — 22 years after the first revelation — the entire Arabian Peninsula had embraced Islam. Within a century:

• 633–638 CE: The Levant (modern Syria, Jordan, Palestine) entered the Muslim world.
• 636 CE: Persia (the Sassanid Empire) was decisively defeated at the Battle of al-Qadisiyyah.
• 641 CE: Egypt was incorporated, bringing one of the ancient world's great civilizations into the Islamic sphere.
• 711 CE: Muslim armies crossed into the Iberian Peninsula, where an Islamic civilization would flourish for nearly 800 years.
• 750 CE: The Abbasid Caliphate, centered in Baghdad, became the heart of a golden age of Islamic science, philosophy, and art.

This spread happened through a combination of sincere religious conviction, trade networks, diplomatic alliances, and military expansion. But the core driver was the message itself: one God, direct access to Him without clergy, universal human brotherhood, and clear moral guidance.

For deeper context on the first caliphs who led the community after the Prophet's death, DeenBack's guide to the first caliphs of Islam is an excellent companion read. And for how Islamic history shapes Muslim identity today, DemiManifest explores that connection with a modern lens.

You can explore the first revealed verses of the Quran directly at Quran.com (Surah Al-Alaq, 96), and find the founding hadith narrations at Sunnah.com.

Understanding the Founding Moment in Your Own Life

Knowing when Islam was founded is not merely historical knowledge — it connects you to something alive and ongoing. When you recite Surah Al-Alaq in salah, you are reciting the very first words of revelation. When you fast in Ramadan, you are honoring the same sacred month in which the Quran first descended. When you begin anything with Bismillah — "in the name of Allah" — you echo the command given in that cave: Iqra bismi rabbik.

The Prophet ﷺ said: "I have been sent to complete the noble character" (Al-Muwatta 1614). Understanding the founding moment helps you see that Islam did not arrive to replace what was good in the world, but to complete it.

For more on the prophetic life that defined these early years, our guide on who was Prophet Muhammad is essential reading. And to understand the pivotal night that preceded the public mission, see the Night of Isra and Miraj.

Common Questions About When Islam Was Founded

Does "Islam" refer to a 7th-century religion or something older? Both — depending on the framework. Historically, Islam as a organized community with a complete scripture dates to 610 CE and was completed by 632 CE. Theologically, Islam as submission to Allah is described in the Quran as the religion of all the prophets from Adam onward.

Why do some historians place the founding later than 610 CE? Some historians focus on 622 CE (the Hijra) or 630 CE (the Conquest of Mecca) as the effective founding of Islam as a political entity. Islamic tradition, however, identifies 610 CE as the true beginning because it marks the first Quranic revelation — which is the theological foundation of the faith.

Is the date of 610 CE historically documented outside of Muslim sources? Yes. The approximate dates of the first revelation and the Prophet's life are corroborated by Byzantine chronicles, Persian records, and Jewish sources from the period, as well as by Yaqeen Institute research on the historical reliability of early Islamic sources.

The Founding That Still Shapes a Billion Lives

Islam was founded in 610 CE — not as a new invention, but as the final chapter of a divine message sent through prophets throughout human history. What began with five verses in a cave in Mecca is today the faith of approximately 1.9 billion people across every continent.

This is not coincidence. It is, as Muslims believe, the fulfillment of Allah's promise: "Indeed, it is We who sent down the Quran, and indeed, We will be its guardian" (Surah Al-Hijr, 15:9). The founding moment still speaks — in every salah, every recitation, every dua made in the name of the Lord who created.