World Religions › Medieval
Islam
From AD 610 (first revelation, by tradition)· Religion or tradition· Judaism, Christianity & Islam
Mostly agreed by scholarsMost historians agree; some details uncertain.
The faith of submission (islam) to the one God, Allah, revealed, Muslims believe, through the Prophet Muhammad; about 2 billion followers.
See it on the World Religions map →What it is
Muslims believe God sent many prophets, including Abraham, Moses and Jesus, and that Muhammad was the last, receiving the Quran from 610 to 632. Core beliefs are God's absolute oneness, angels, scriptures, prophets, the Day of Judgment and divine decree; practice centers on the Five Pillars. Within a century of Muhammad's death, Muslim rule stretched from Spain to Central Asia. About 85–90% of Muslims are Sunni; the largest Muslim populations are in Indonesia, Pakistan, India and Bangladesh.
Why it matters
It is the world's second-largest religion, about 25% of humanity in 2020 (Pew), and the fastest-growing, shaping law, art, science and politics across three continents for 1,400 years.
Sources and history
Early Quran manuscripts (the Birmingham leaves are carbon-dated to about 568–645), inscriptions, coins and papyri from the 600s, later Muslim histories, and Pew Research population estimates.
Questions and debates
Historians debate how Islam's doctrines and institutions took shape in its first two centuries, and how quickly conquered peoples converted; most evidence suggests it took centuries.
Inside this (10)
Connections (12)
▸Islam reveres Abraham, shared ancestor of Jews, Christians and MuslimsHistorical record
The connection
Islam calls Abraham (Ibrahim) the 'friend of God' and a hanif, a pure monotheist who was 'neither Jew nor Christian' but submitted to God. Muslims invoke him in their daily prayers, retrace his family's steps on the Hajj, and remember his willingness to sacrifice his son at Eid al-Adha.
When and where
In the Quran, 610–632, which names Abraham about 69 times and titles sura 14 after him; and in Muslim prayer and pilgrimage ever since.
Historical evidence
The Quran's text, the standard wording of Muslim prayer, and the Hajj and Eid rituals all document this reverence directly.
Questions and debates
Muslims usually identify the son Abraham nearly sacrificed as Ishmael, not Isaac as in the Bible; the Quran does not name him, and early commentators disagreed.
▸Resurrection of the dead and Last Judgment became core doctrine in IslamHistorical record
The connection
Belief in the Last Day is one of Islam's six articles of faith. The Quran describes the dead rising bodily, every person's deeds weighed, and a final verdict of paradise or hell. It shares this teaching with Judaism and Christianity, and Muslims see it as the same divine message, renewed.
When and where
Throughout the Quran, especially early Meccan suras (610–622) such as sura 75, 'The Resurrection', and sura 81, which warn of the coming Day.
Historical evidence
The Quran devotes hundreds of verses to the Day of Judgment; hadith and creeds list it among required beliefs, and surveys find nearly all Muslims affirm it.
Questions and debates
Historians debate how much Jewish, Christian and Zoroastrian ideas circulating in Arabia shaped this imagery; Muslims hold it as fresh revelation from God.
▸Islam teaches strict Monotheism: belief in one GodHistorical record
The connection
Islam's central doctrine is tawhid, God's absolute oneness. The short sura 112 declares God 'One, eternal, neither begetting nor begotten, with none like Him.' Associating anything with God (shirk) is the gravest sin. That is why Islam rejects the Christian Trinity and keeps images out of worship.
When and where
Preached by Muhammad from about 610 in Mecca, then a polytheist city whose Kaaba held many idols, which he removed in 630.
Historical evidence
The Quran itself, the shahada recited daily, and the Dome of the Rock's inscriptions of 691/692, which quote sura 112.
Questions and debates
Scholars debate how far pre-Islamic Arabs already knew a high god, Allah, above lesser deities, and who the hanifs, Arabs said to worship one God, really were.
▸Jesus of Nazareth is honored as a prophet in IslamHistorical record
The connection
Muslims believe Jesus (Isa) was one of God's greatest prophets and the Messiah, born of the Virgin Mary, who worked miracles and received a scripture, the Injil. But the Quran denies that he is God's son or divine, and says he was not crucified but raised to God. Many Muslims expect his return before the Last Day.
When and where
In the Quran (610–632), which names Jesus 25 times and Mary more often than the New Testament does; sura 19 is named after her.
Historical evidence
The Quran's text honors him directly; hadith and Muslim creeds elaborate his role, including his expected return.
Questions and debates
Historians debate how Christian ideas reached Arabia. Muslims and Christians disagree on the crucifixion, which most historians count among the surest facts about Jesus.
▸Muhammad is revered as the final prophet of IslamHistorical record
The connection
Muslims believe Muhammad is the 'Seal of the Prophets', the last in a line from Adam through Abraham, Moses and Jesus, and that through him God's message was completed. His words and example, the Sunna, are, after the Quran, the main guide to Muslim belief and practice.
When and where
Mecca and Medina, 610–632; the Quran (33:40) calls him 'the Messenger of God and the seal of the prophets'.
Historical evidence
The Quran, the shahada recited daily, and the hadith collections show this belief from Islam's earliest records; Sunni and Shia Muslims both hold it.
Questions and debates
Some scholars note 'seal' could mean confirmation rather than last; the Ahmadiyya movement reads it differently, and Pakistan declared Ahmadis non-Muslim in 1974.
▸The Quran is the scripture of IslamHistorical record
The connection
For Muslims the Quran is God's literal speech, the final revelation, and the supreme source of belief, worship and law. It is recited in Arabic in every prayer, memorized by millions, and read in full during Ramadan. Every Islamic school of thought claims to be grounded in it.
When and where
From the first revelation in 610 onward; standard text around 650; today's standard printed text descends from the Cairo edition of 1924.
Historical evidence
Universal Muslim practice, the earliest manuscripts, and Islamic law and theology, which all cite the Quran as their first source.
Questions and debates
Muslims debate literal versus contextual interpretation today; in the 800s, theologians fiercely argued whether the Quran was created or eternal.
▸The Hijra to Medina starts the calendar of IslamHistorical record
The connection
Muslims count years AH, 'after the Hijra', because 622 marked the founding of an independent Muslim community. The Islamic calendar is purely lunar, about 11 days shorter than the solar year, so Ramadan and the Hajj move through all the seasons over about 33 years.
When and where
Adopted by Caliph Umar around 638 (year 17 AH), counting from the start of the lunar year in which the Hijra occurred.
Historical evidence
A Greek-Arabic papyrus dated year 22 (AD 643) already uses the Hijri era, and dated coins and inscriptions follow.
Questions and debates
Why Umar chose the Hijra over Muhammad's birth or first revelation rests on later accounts; the calendar's 1 Muharram is not the Hijra's actual date, which came months later.
▸Five Pillars of Islam are the core practices of IslamHistorical record
The connection
The pillars turn belief into routine: faith declared, five daily prayers, yearly charity, a month of fasting and a once-in-a-lifetime pilgrimage. They bind Muslims to God and to one another; a person who sincerely says the shahada becomes a Muslim.
When and where
Commanded across the Quran (610–632), practiced in Muhammad's community at Medina, and listed as five in hadith collected by the 800s.
Historical evidence
Fourteen centuries of Muslim practice; Pew's 2012 survey of 39 countries found most Muslims fast during Ramadan, while daily prayer varies widely by country.
Questions and debates
How strictly each pillar must be kept, for example whether a Muslim who neglects prayer remains a believer, has been debated by scholars for centuries.
▸Sufism, Islamic mysticism is the mystical path of IslamHistorical record
The connection
Sufis see themselves not as a separate sect but as seekers of Islam's inner dimension (ihsan): worshiping God 'as if you see Him', in a hadith's words. Most Sufis also follow Sunni or Shia law. Al-Ghazali (d. 1111) reconciled Sufism with mainstream theology, and orders became part of everyday Muslim life.
When and where
Iraq from the 700s (Basra, Baghdad), spreading across the Muslim world; orders like the Qadiriyya (1100s) and Naqshbandiyya (1300s).
Historical evidence
Al-Ghazali's Revival of the Religious Sciences and other Sufi texts; order genealogies and lodges still active from Senegal to Indonesia.
Questions and debates
Salafi and Wahhabi critics call shrine veneration un-Islamic, and some Sufi shrines have been attacked; how many Muslims belong to Sufi orders is unknown.
▸Sikhism arose amid Hinduism and IslamMostly agreed by scholars
The connection
Sikhism arose in Punjab, where Hindu and Muslim cultures met under Muslim rule. Guru Nanak's strict monotheism and rejection of idol worship resemble Islam, and the Sikh scripture includes the Sufi poet Sheikh Farid. Later, Mughal emperors executed Gurus Arjan (1606) and Tegh Bahadur (1675), which pushed Sikhs toward armed self-defense.
When and where
Punjab, from c. 1500 under the Lodi Sultanate and then the Mughal Empire; Guru Nanak's lifelong companion Mardana was Muslim.
How do we know?
Nanak's hymns address Muslims and Hindus alike; the Guru Granth Sahib includes Farid's verses; Mughal sources, including Emperor Jahangir's memoir, record Arjan's execution.
Questions and debates
Scholars reject the old view of Sikhism as a simple Hindu–Muslim blend; how much Islam shaped Nanak, compared with Hindu devotional traditions, is debated.
▸Bahá'í Faith grew out of Shia IslamHistorical record
The connection
The Bahá'í Faith began among Shia Muslims in Iran. Twelver Shia await the return of the hidden Twelfth Imam; in 1844 the Báb claimed to be the 'Gate' to him, and later the promised one himself. Bahá'u'lláh then declared a new revelation. Bahá'ís honor Muhammad as a messenger of God but see their faith as independent.
When and where
Shiraz in 1844, spreading through Qajar Iran; Bahá'u'lláh declared his mission in Baghdad in 1863 while in Ottoman exile.
Historical evidence
The Báb's and Bahá'u'lláh's writings use Shia terms and expectations; Iranian and Ottoman records document the origins and persecution.
Questions and debates
Bahá'ís see their faith as independent of Islam, as Christianity is of Judaism; Iran's government and many Muslim authorities call it heresy, with grave human-rights consequences.
▸Partition of India and Pakistan created Pakistan as a homeland for followers of IslamHistorical record
The connection
The Muslim League argued that India's Muslims were a separate nation (the 'two-nation theory') who would be outvoted in a Hindu-majority India. Britain's 1947 partition created Pakistan, in two wings, East and West, from Muslim-majority regions, while India became a secular state with a large Muslim minority.
When and where
British India, August 14–15, 1947, led on the Muslim side by Muhammad Ali Jinnah's Muslim League; East Pakistan became Bangladesh in 1971.
Historical evidence
The Lahore Resolution (1940), Jinnah's speeches and British records. Violence and migration displaced 10–20 million people; deaths are estimated at 200,000 to 2 million.
Questions and debates
Whether Jinnah wanted an Islamic state or a secular homeland for Muslims is still debated in Pakistan, as is whether partition could have been avoided.