Questions, answered with the evidence

Muslim tradition, following the Qur'an, holds that Abraham and his son Ishmael raised the foundations of the Kaaba, the 'House' at Mecca. History can neither confirm nor refute that. What it can show is that the sanctuary is older than Islam: the Qur'an addresses Quraysh as people who already worship 'the Lord of this House'. No inscription, coin or outside text from before Islam names Mecca or its shrine, so how much older cannot be measured. The building itself has been rebuilt several times: by Quraysh shortly before Muhammad's call, according to the tradition; by Ibn al-Zubayr after a fire in 683; by al-Ḥajjāj in 693 on the earlier plan; and after a flood in the 1620s. The cube standing today is mostly that seventeenth-century rebuilding.

Yes, as far as historians can tell. Almost every specialist, Muslim or not, accepts that Muhammad was a historical person who preached in Mecca, led a community in Medina from 622 and died around 632. The strongest evidence comes from outside the Muslim tradition: a Syriac Christian chronicle written about 640 records a battle in 634 fought by the Arabs of Muhammad, and an Armenian history of the 660s describes him as a merchant who taught the Arabs the God of Abraham. The Qur'an names him, Muslim documents count years from his emigration by 643, and a coin of 685–686 proclaims him God's messenger. What historians debate is not whether he lived but how much of the later biography can be trusted.

The sources that give her age are hadith in the two most authoritative Sunni collections, al-Bukhārī's and Muslim's, compiled in the ninth century and mostly in ʿĀʾisha's own voice: she was six, or in one version seven, when the marriage was contracted, and nine when she moved to Muhammad's house. Ibn Saʿd and al-Ṭabarī give the same ages. Most chains of transmission run through Hishām ibn ʿUrwa, a Medinan scholar who died around 763. Classical Muslim scholars accepted the report. Since the twentieth century some Muslim writers have recalculated her age into her later teens, and in 2022 the historian Joshua Little argued that the report began with Hishām in Iraq. Historians cannot settle her actual age from the surviving evidence.

The oldest surviving Qur'an leaves come from the seventh century, within a few decades of Muhammad's death in 632. No complete Qur'an survives from that time, and none carries a written date, so the oldest copies are dated by radiocarbon testing of their parchment. Two leaves in Birmingham give 568–645, a leaf of the Ṣanʿāʾ palimpsest 578–669, a Berlin manuscript 606–652 and a Tübingen fragment 649–675, each at about 95% probability. The test dates the animal skin, not the ink, so the writing is likely somewhat later. Their text is almost entirely the one printed today; the erased lower text of the Ṣanʿāʾ palimpsest shows that at least one different version was also copied.

The phrase refers to an episode reported in several early Muslim biographies and commentaries. After naming the three Meccan goddesses al-Lāt, al-ʿUzzā and Manāt (Qur'an 53:19–20), Muhammad is said to have recited two further lines praising them as 'the exalted cranes, whose intercession is to be hoped for'; the Meccans rejoiced, and then the angel Gabriel told him Satan had put the words on his tongue. Shahab Ahmed found that early transmitters widely accepted the story; objections were raised from the tenth century, and by the thirteenth scholars generally rejected it as incompatible with the Prophet's protection from error. The English name is modern, and Salman Rushdie's 1988 novel took its title from it.

The empire was; the religion mostly was not. The Arab conquests of the 630s and 640s took Syria, Iraq, Egypt and Iran by war, with killing, captivity and enslavement. But the conquered were not, in general, required to convert: Christians, Jews and Zoroastrians kept their religions as protected subjects who paid a poll tax, and Muslims were a minority in most conquered lands for one to three centuries or more. Conversion came through taxes, status, marriage, slavery and conviction, with episodes of coercion in particular times and places. In South and Southeast Asia and West Africa, where most Muslims live today, Islam spread largely through traders, rulers and teachers, often long after any conquest.

Abū Bakr (632–634), ʿUmar (634–644), ʿUthmān (644–656) and ʿAlī (656–661), all early converts from Muhammad's tribe of Quraysh and all linked to him by marriage. Sunni Muslims call them the 'rightly guided' caliphs; Shia Muslims hold that ʿAlī should have succeeded first. In thirty years they turned Medina's rule over Arabia into an empire from Egypt to Iran, but three of the four were killed, and the last two reigns ended in civil war. Their title is itself debated: the tradition says it meant 'successor of the messenger of God', while the earliest documents call the ruler 'commander of the believers', and Umayyad coins later say 'God's deputy'.

It began as a political dispute over who should lead the community after Muhammad died in 632, and only slowly became a religious division. Those who held that leadership belonged to Muhammad's cousin and son-in-law ʿAlī and his descendants became the Shia, from shīʿat ʿAlī, ʿAlī's party; those who accepted the first four caliphs in turn became the Sunnis. The killing of ʿAlī's son al-Ḥusayn at Karbalāʾ in 680 gave the Shia their central story. Separate doctrines of authority, law, hadith and public ritual took shape between the eighth and tenth centuries. Later states, above all Safavid Iran from 1501, made the line geographical. Today about 10–13 per cent of Muslims are Shia.

On 10 Muḥarram 61 AH, 10 October 680, an army of the Umayyad caliph Yazīd surrounded al-Ḥusayn, the son of ʿAlī and grandson of Muhammad, at Karbalāʾ on the Euphrates, cut his small company off from water and killed almost all of them. Al-Ḥusayn had refused allegiance to Yazīd and set out for Kufa, whose men had invited him to lead them. The outline is not in doubt; the detailed story comes mainly from an eighth-century Kufan historian and already reads as a martyrdom. Karbalāʾ turned loyalty to ʿAlī's family into a religious identity. Its annual commemoration on ʿĀshūrāʾ grew over centuries, from public mourning in Baghdad in 963 to the passion plays of Safavid and Qajar Iran.

No source from the time of its builder, the Umayyad caliph ʿAbd al-Malik, says why the Dome of the Rock was built, so every answer is an inference. Its own inscription, completed in 691–692, is the earliest evidence: a long Qur'anic text addressed to Christians, denying that God is 'Three' and calling Jesus a messenger of God. Most historians therefore read the building as Islam's answer to Christianity in its holy city, and as part of a wider programme in which ʿAbd al-Malik put the Prophet and the Qur'an on coins, roads and monuments. A ninth-century report that he meant it to replace the pilgrimage to Mecca, then held by his rival Ibn al-Zubayr, is disputed. Its link with Muhammad's night journey appears to be later.

Sharia (sharīʿa, 'the path') is God's law as Muslims understand it: the right way of acting, as God wills it. Muslim scholars always distinguished it from fiqh, 'understanding', the human and fallible effort to work out what that law requires. For most of Islamic history the law was not a code issued by a ruler but a body of interpretation built by scholars, recorded in books that set out the differing opinions of the schools, and applied by judges alongside custom and the ruler's own regulations. The four Sunni schools took their lasting form between about 870 and 950. The first state code of Islamic law was the Ottoman Mecelle of 1869–1876; most of what is now called 'sharia law' is a product of modern states.

Sufism is the mystical tradition within Islam: a path of renunciation, constant remembrance of God (dhikr) and love of God, aimed at the self's passing away in God and its return to the world. It is not a sect. It began with eighth-century renouncers in the garrison cities of Iraq, took its name in ninth-century Baghdad, where 'Sufi' most probably meant a wearer of wool, and was argued into the mainstream of Sunni learning by manuals of the tenth and eleventh centuries and by al-Ghazālī. From the twelfth century it became institutional, in lodges and in orders such as the Qādiriyya, Chishtiyya and Mevleviyya. Its cult of saints and tombs has had critics from Ibn Taymiyya to the Wahhabis.

Ahmadis regard themselves as Muslims; most other Muslims, and the law of Pakistan, do not. The Ahmadiyya movement began in the Punjab in 1889 with Mirza Ghulam Ahmad, who claimed to be the Promised Messiah and the Mahdī and called himself a prophet bringing no new law, subordinate to Muhammad. Most Muslims understand the Qur'an's 'seal of the prophets' to mean that no prophet of any kind can follow Muhammad, so they consider the claim incompatible with Islam. Since 1974 Pakistan's constitution has defined Ahmadis as non-Muslims, and since 1984 its penal code has made it an offence for them to call their faith Islam. Whether they are Muslims is a theological question; history can show how the dispute arose and how states came to settle it.

'Wahhabism' is the name outsiders gave to the reform movement of Muḥammad ibn ʿAbd al-Wahhāb (1703–1792), a Ḥanbalī scholar of Najd in central Arabia. He taught a strict understanding of tawḥīd, God's oneness, and condemned calling on saints, vowing offerings at tombs and similar practices as shirk, associating partners with God. In 1744 he made a pact with the ruler Muḥammad ibn Saʿūd, the alliance behind all three Saudi states. His followers call themselves muwaḥḥidūn, 'those who affirm God's oneness', or simply Muslims, and many now say Salafi. Whether the founder was a mainstream reformer or a militant, and how far later jihadis draw on him, are argued.

The Nation of Islam is an African American religious movement founded in Detroit in 1930 by Wallace Fard Muhammad and led from 1934 to 1975 by Elijah Muhammad. It taught that Black Americans were the original people and Muslims by nature, that Fard had been God in person and Elijah his messenger, and that the white race had been created by an evil scientist. Those teachings contradict the core beliefs of Sunni and Shia Islam, and Muslim scholars rejected them. Its most famous preacher, Malcolm X, left it in 1964 and became a Sunni Muslim. When Elijah Muhammad died in 1975, his son W. D. Mohammed led most members into Sunni Islam; from 1977 Louis Farrakhan rebuilt a Nation of Islam on the older teachings.

Veiling is older than Islam: in the ancient Near East and in the Byzantine and Persian empires it marked women of rank. The Qur'an tells believing women to draw their head-coverings over their necklines and to wear outer garments, and uses the word ḥijāb not for clothing but for a screen between the Prophet's wives and visitors. Over the following centuries jurists turned these verses into rules of dress, and veiling became a mark of urban women of status. In the twentieth century many urban women unveiled, by choice in Egypt from 1923 and by force in Iran from 1936. From the 1970s a new style of headscarf spread among students and professionals, and states since then have both required it and banned it.