Short-answer box
Islam began as a historical community in early seventh-century Arabia. The date most often given is 610 CE, the traditional date of the first revelation received by Muhammad in Mecca. But there is a second date that matters just as much: 622 CE, the year of the Hijra, the migration of Muhammad and his followers from Mecca to Medina. The Hijra marks the start of the Islamic calendar, so 622 CE is year 1 in that calendar.
There is also a third answer, and it comes from within the tradition itself. Muslims understand Islam not as a brand new religion invented in the seventh century, but as the restoration of the monotheism taught by earlier prophets, including Abraham, Moses, and Jesus. In that telling, the faith is older than its seventh-century community. Historians, working from the surviving evidence, date the community itself to the early 600s CE. All three answers are correct in their own frame, and this article explains each one, so that the date you pick depends on what you mean by “begin.”
Why there are three answers
Asking when Islam began sounds like a question with one date, but the sources give three, because “begin” can mean three different things.
First, it can mean the moment the message started. By that measure, the answer is 610 CE, when, according to Islamic tradition, Muhammad received his first revelation in a cave outside Mecca.
Second, it can mean the moment a distinct community with its own institutions came into being. By that measure, the answer is 622 CE, when Muhammad and his followers moved to Medina and formed a community governed by its own agreements. That is why the Islamic calendar counts its years from 622, not from 610.
Third, it can mean the beginning of the faith as Muslims themselves understand it. Islam teaches that its message restores the worship of one God taught by earlier prophets, so in the tradition’s own telling, the faith did not start from nothing in the seventh century. It returned to something ancient.
A good answer keeps these three apart instead of picking one and hiding the others. The rest of this article follows them in order: the Arabia into which Islam was born, the life of Muhammad, the revelation, the move to Medina, the community that grew from it, and the way historians today date all of it.
Arabia before Islam
To understand when Islam began, it helps to picture the Arabia of around 600 CE. The Arabian Peninsula had no single government. It was a land of tribes, caravan routes, and oasis towns, sitting between two great empires: the Byzantine Empire to the northwest and the Sasanian Empire of Persia to the northeast. Both empires were exhausted by long wars with each other, a fact that later mattered a great deal for how far and how fast Islam spread.
Mecca, in western Arabia, was a prosperous trading city. Its wealth came from the caravan trade, and from the Ka’ba, a shrine and place of pilgrimage that housed the deities worshipped by the Arabs of the time. The Metropolitan Museum of Art’s history of the period describes Mecca’s wealth and influence as based on exactly these two things: trade and the shrine.
Religiously, most people on the peninsula worshipped many gods. But Arabia was not religiously uniform. There were established Jewish communities and Christian communities in the region, and the monotheistic idea was already present. Islam emerged, in the Met’s words, in a polytheistic environment, and its central claim, belief in one God alone, stood in sharp contrast to the many gods honored at Mecca’s shrine. That contrast is the key to everything that followed, including the opposition Muhammad faced.
Muhammad’s early life
Muhammad was born in Mecca around 570 CE, into the tribe of Quraysh, the tribe that controlled the city’s trade and its shrine. The date is approximate: the sources give it as circa 570, and historians treat it as traditional rather than exact. He was orphaned young and raised first by his grandfather and then by his uncle Abu Talib.
As a young man, Muhammad worked as a merchant in Mecca’s caravan trade and earned a reputation for honesty. He married Khadijah, a successful Meccan merchant, who supported him throughout his mission. Tradition names Khadijah, his cousin Ali, and his close friend Abu Bakr among the first to accept his message.
The name of the new faith is itself part of the story. The Arabic word “Islam” means submission, in this case submission to God, and a “Muslim” is one who submits. The faith, as Muhammad preached it, was not presented as the worship of a new or different God. Allah is the Arabic word for God, the same creator God honored by Jews and Christians, and the message was that this one God alone should be worshipped.
The first revelation: 610 CE
According to Islamic tradition, Muhammad regularly withdrew to a cave on Mount Hira, outside Mecca, for prayer and reflection. In 610 CE, when he was about 40 years old, he received his first revelation there. Muslims believe that the archangel Gabriel appeared to him and commanded him to recite, beginning with the words “Recite in the name of thy Lord” (Sura 96 of the Qur’an).
This is the date most commonly given as the beginning of Islam, and it is the one the Metropolitan Museum of Art uses: Muhammad “received his first revelation in 610.” It is worth stating plainly what kind of date this is. The Qur’an itself gives no calendar dates. The year 610 comes from the early Islamic biographical tradition, the sira, which was written down later. Historians accept the early seventh century as the period, and 610 as the traditional year, while noting that the exact year cannot be verified from documents written at the time.
The revelations continued, according to tradition, for about 23 years, until Muhammad’s death in 632. They were memorized and written down by his followers, and later collected into the Qur’an, a word that literally means “recitation” in Arabic. Muslims regard the Qur’an as the literal word of God, revealed in classical Arabic, and it remains the central religious text of Islam. It is organized into 114 chapters, called suras, made up of verses.
For the first few years, Muhammad taught privately. Public preaching began around 613 CE. His message combined strict monotheism with a strong social ethic: care for widows, orphans, and the poor, honesty in trade, and rejection of the idols housed in the Ka’ba. That last point was explosive in Mecca, because the shrine’s pilgrimage traffic was a major source of the city’s wealth, and the leaders of Quraysh saw the new preaching as a threat to their power, their customs, and their income.
Opposition in Mecca and the Hijra: 622 CE
The opposition hardened. Muhammad’s followers faced persecution, including social ostracism, economic pressure, and violence. The Meccan leadership organized a boycott of Muhammad’s clan. Some of his followers sought refuge across the Red Sea in Abyssinia, in what is now Ethiopia.
The turning point came in 622 CE. Leaders in the oasis town of Yathrib, about 200 miles north of Mecca, invited Muhammad to come and arbitrate their feuds. Muhammad and his followers migrated there, an event known as the Hijra, from the Arabic word for emigration. Yathrib became known as Medina, short for “City of the Prophet.”
The Hijra matters for two reasons, and both are why 622 is a serious rival to 610 as the answer to this article’s question. First, it was in Medina that the Muslim community became a political and social entity in its own right. On arrival, Muhammad negotiated an agreement with the local clans, known as the Constitution of Medina, which, in Encyclopaedia Britannica’s words, established the Muslim community as a sociopolitical entity for the first time. The community, the umma, now had its own agreements, its own leadership, and its own identity.
Second, 622 is the year the Islamic calendar starts from. Muhammad himself did not date his letters and treaties from the Hijra. It was Umar, the second caliph, who in 639 CE introduced the Hijra era as the calendar of the community. He set its first year to begin on the first day of the lunar month of Muharram, which corresponds to July 16, 622, on the Julian calendar. The era is marked AH, from the Latin anno Hegirae, “in the year of the Hijra.” So when Muslims say an event happened in, for example, the year 100 AH, they are counting from the migration to Medina.
In short: 610 is when the message began, and 622 is when the community began. Both dates are right, and they answer different questions.
Medina, the return to Mecca, and Muhammad’s death
Medina changed the movement’s fortunes. Muhammad continued to attract followers, built a mosque whose courtyard-centered design became the prototype for later mosques, and led a community that now included both the emigrants from Mecca and the Medinese who had welcomed them, known as the ansar, or “helpers.”
Conflict with Mecca continued. The early Muslim community fought the Meccans at Badr in 624 CE, a Muslim victory, and at Uhud in 625, which ended without a clear result. In 627, a confederation of tribes besieged Medina in the Battle of the Trench. In 628, Muhammad and the Meccans agreed to the Treaty of Hudaybiyyah, a truce that, among other things, allowed Muslims to make pilgrimage to Mecca. When the truce broke down, Muhammad marched on Mecca, and in 630 the city surrendered with little bloodshed.
One of his first acts on returning, the Met records, was to cleanse the Ka’ba of its idols and rededicate the shrine to Allah. The shrine that had once housed many gods became the central place of worship for Muslims, and Mecca became the direction of Muslim prayer and the destination of pilgrimage.
Muhammad died in Medina in 632 CE, at about 62 years old. By then, the tribes of Arabia had largely been brought under a single religious community. He left no son and no named successor, and the question of who should lead the community next would shape the next century of Islamic history.
What the new faith taught
By the time of Muhammad’s death, the shape of Islamic practice was established, and it is worth setting it out briefly, because it explains what “Islam” meant to the community that now carried the name.
At its center is the Qur’an, together with the example of Muhammad, known as the Sunna, which is recorded in reports called hadith. The Qur’an was not compiled into a single volume during Muhammad’s lifetime. According to tradition, it was gathered under the first caliph, Abu Bakr, from the written fragments and memories of his companions, and a standard text was established under the third caliph, Uthman, who appointed a committee in 651 to 652 CE, under Zayd ibn Thabit, one of Muhammad’s scribes, to reconcile the available versions.
The best known summary of Islamic practice is the Five Pillars, the acts of worship that Sunni Islam in particular treats as obligatory for all Muslims, and that Shia Muslims also recognize as fundamental, though their own lists of duties are organized differently. They are:
- Shahada, the profession of faith: that there is no god but God, and that Muhammad is his messenger.
- Salah, prayer, performed five times a day at fixed times.
- Zakat, almsgiving, a fixed portion of qualifying wealth (commonly 2.5 percent) given to those in need.
- Sawm, fasting from dawn to sunset during the month of Ramadan.
- Hajj, pilgrimage to Mecca, required once in a lifetime for Muslims who are physically and financially able.
These pillars are the shared core of Muslim practice across the world, and they were taking shape in the Medina years. They also show why the Hijra matters so much: prayer, fasting, almsgiving, and pilgrimage are community practices, and they needed a community to practice them in.
After 632: caliphs, conquests, and a world religion
After Muhammad’s death, leadership passed to a series of four caliphs, from the Arabic khalifa, meaning “successor,” known as the Rightly Guided caliphs: Abu Bakr (632 to 634), Umar (634 to 644), Uthman (644 to 656), and Ali (656 to 661). Under their command, Arab armies carried Islam out of Arabia. The Met’s account lists the results plainly: Syria, Palestine, and Egypt were taken from the Byzantine Empire, while Iraq and Iran, the heart of the Sasanian Empire, fell as well. The exhaustion of those two empires, and the appeal of the new faith’s message and its relatively light demands on conquered peoples, helped the expansion move fast.
It moved very fast. Within a hundred years of Muhammad’s death, the Met notes, the caliphs controlled lands reaching from Spain to present-day Pakistan. The Umayyad caliphate, founded by Mu’awiya after Ali’s death, ruled from Damascus from 661 to 750. The Abbasid caliphate replaced it in 750 and ruled from Baghdad until the Mongol sack of the city in 1258. By then, Islam was no longer an Arabian religion. It was a world civilization, with its own law, scholarship, architecture, and trade networks stretching from West Africa to Southeast Asia.
That spread is also why the question “when did Islam begin” has a geographical footnote. Islam began in Arabia, but most Muslims today do not live there. About a fifth of the world’s Muslims live in the Arab world. The largest Muslim populations are in South and Southeast Asia, and Indonesia is the country with the largest Muslim population, with more than 230 million Muslims.
The Sunni and Shia split
One more date belongs in any honest account of Islam’s beginnings, because it shaped the religion permanently: the split between Sunni and Shia Muslims.
The split began as a dispute about succession. When Muhammad died in 632, Abu Bakr was chosen as caliph. A minority favored Ali, Muhammad’s cousin and son-in-law, and they became known as the partisans of Ali, or Shiat Ali. Ali did become caliph eventually, as the fourth caliph in 656, but his rule was marked by civil war, including the Battle of Siffin in 657 against Mu’awiya, the governor of Syria. Ali was assassinated in 661.
The division hardened in 680, when Husayn, Ali’s son and Muhammad’s grandson, was killed with his followers at Karbala, in what is now Iraq, after challenging the caliph Yazid. Karbala became a central place of pilgrimage and mourning for Shia Muslims, and the split between the two branches deepened permanently.
Today, Sunnis form the large majority of Muslims, roughly 87 to 90 percent, while Shia Muslims form roughly 10 to 13 percent, with Shia majorities in Iran, Iraq, Bahrain, and Azerbaijan. The two branches share the Qur’an, the Five Pillars in their essentials, and the core beliefs of the faith, and they differ on the question of rightful leadership after Muhammad and on the religious authority that flows from it. Both branches trace themselves to the same seventh-century beginning.
How historians date the beginning
A careful reader will have noticed a pattern in this article: many dates are described as “traditional” or “according to tradition.” That is deliberate, and it reflects how historians work on this period.
The Qur’an itself contains no calendar dates for these events. The narrative of Muhammad’s life comes from the sira, the biographical literature, and from hadith reports, which were compiled in written form more than a century after the events they describe. Historians therefore treat the traditional chronology, 610 for the first revelation, 622 for the Hijra, 632 for Muhammad’s death, as the framework handed down by the community itself, and they accept the broad shape, a new monotheistic movement emerging in western Arabia in the early seventh century, as secure. The exact year of any single event, including Muhammad’s birth year of about 570, is harder to pin down, and scholars disagree on details.
None of this makes the traditional dates wrong. It means they belong to a different kind of evidence than, say, a dated inscription or a contemporary chronicle. When this article says “traditionally dated,” it is marking that distinction honestly, not casting doubt on the events. The community, the calendar, the scripture, and the civilization that followed are all firmly in the historical record from the seventh century onward.
Islam today
Pew Research Center’s June 2025 study of the world’s religious landscape found that Muslims numbered about 2 billion in 2020, or 25.6 percent of the world’s population, up from 23.9 percent in 2010. Islam was the fastest-growing major religious group in that decade, growing by about 347 million people, and the growth came mainly from higher birth rates and a younger age profile, not from conversion. Muslims are the second largest religious group in the world after Christians.
That is a long way from a small community in Mecca and Medina in the 620s. It is also why the question in this article’s title keeps being asked: a faith that began with one man’s preaching in a trading town now shapes the daily lives of a quarter of humanity, and its beginning, 610 or 622, is the starting point of that story.
Frequently asked questions
Was Islam founded in 610 or 622?
Both dates are used, for different reasons. 610 CE is the traditional date of the first revelation, the beginning of the message. 622 CE is the year of the Hijra, the migration to Medina, which marks the beginning of the Muslim community and the start of the Islamic calendar. If you mean the message, say 610. If you mean the community and the calendar, say 622.
Why does the Islamic calendar start in 622 instead of 610?
Because the calendar counts from the founding of the community, not from the first revelation. The second caliph, Umar, introduced the Hijra era in 639 CE, setting its first year to the year of the migration. The calendar is lunar, so Islamic years are about 11 days shorter than solar years, and Islamic dates drift through the seasons over time.
Who was the first Muslim?
Tradition names Muhammad’s wife Khadijah, his cousin Ali, and his friend Abu Bakr among the first to accept his message. Muslims also understand the question differently: since Islam means submission to God, Muslims regard earlier prophets, including Abraham, as Muslims in that sense, even though the historical community began in the seventh century.
Was Muhammad the founder of Islam?
Muslims do not describe him that way. In Muslim belief, Muhammad is the final prophet in a line that includes Adam, Noah, Abraham, Moses, and Jesus, and his role was to receive and deliver God’s final message, not to invent a new God. Historians, writing outside the tradition, often call him the founder of Islam as a historical community, because the community formed around his preaching. Both descriptions refer to the same person and the same events.
Is Islam the youngest major world religion?
It is younger than Judaism, Christianity, Hinduism, and Buddhism, all of which predate it by centuries or more. But it is not the youngest religion overall: Sikhism began in the fifteenth century, and the Baha’i Faith in the nineteenth, both after Islam.
Did Islam begin with Abraham?
In Muslim belief, yes, in the sense that Islam restores the monotheism taught by Abraham. Historically, the community that calls itself Muslim began in seventh-century Arabia. The two statements answer different questions, one about faith and one about history, and they are not in conflict once that distinction is clear.
Keep reading: Is Islam and Muslim the Same?
Sources & references
- The Metropolitan Museum of Art, Heilbrunn Timeline of Art History, "The Birth of Islam," by Suzan Yalman, based on work by Linda Komaroff (October 2001). https://www.metmuseum.org/essays/the-birth-of-islam
- The Metropolitan Museum of Art, "Introduction," Art of the Islamic World, Unit One. https://www.metmuseum.org/learn/educators/curriculum-resources/art-of-the-islamic-world/unit-one/introduction
- Encyclopaedia Britannica, "Hijrah." https://www.britannica.com/event/Hijrah-Islam
- Infoplease, "Qur'an" (encyclopedia entry). https://www.infoplease.com/encyclopedia/religion/islam/general/quran
- University of Nevada, Reno, "History of Muhammad," in World Religions (Pressbooks). https://unr.pressbooks.pub/worldreligions/chapter/history-4/
- EBSCO Research Starters, "Husayn." https://www.ebsco.com/research-starters/military-history-and-science/husayn
- Oxford University Press blog, "Hussein ibn Ali killed at Karbala" (October 10, 2011). https://blog.oup.com/2011/10/hussein/
- Pew Research Center, "How the Global Religious Landscape Changed From 2010 to 2020" (June 2025). https://www.pewresearch.org/wp-content/uploads/sites/20/2025/06/PR_2025.06.09_global-religious-change_report.pdf, reporting about 2 billion Muslims in 2020, 25.6 percent of the world population (up from 23.9 percent in 2010), and Indonesia's 239 million Muslims in 2020 (see also https://www.pewresearch.org/religion/2025/06/09/muslim-population-change/). Sunni and Shia shares from Pew's earlier global Muslim population mapping.
