In little more than a century, Arab armies carrying a new faith built one of the largest empires the world had ever seen — from the Atlantic to the Indus.
Stop 01 · c. 600–610
Arabia on the Eve of Islam
In 600 CE the Arabian Peninsula sat between two superpowers, the Byzantine and Sasanian empires, which would soon exhaust each other in a ruinous war (602–628). Persian armies took Damascus in 613 and Jerusalem in 614, overran Egypt for the first time and in 626 joined Avars and Slavs in a failed siege of Constantinople, before Emperor Heraclius struck into Persia and won at Nineveh in 627. Arabia itself was a patchwork of tribes, trading towns and faiths: most Arabs worshipped many gods, alongside Jewish, Christian and Zoroastrian communities. Into this world, in the city of Mecca, home of the Kaaba shrine, the Prophet Muhammad of the Quraysh tribe began preaching around 610 CE.
In 600 CE the Arabian Peninsula sat between two superpowers, the Byzantine and Sasanian empires, which would soon exhaust each other in a ruinous war (602–628). Persian armies took Damascus in 613 and Jerusalem in 614, overran Egypt for the first time and in 626 joined Avars and Slavs in a failed siege of Constantinople, before Emperor Heraclius struck into Persia and won at Nineveh in 627. Arabia itself was a patchwork of tribes, trading towns and faiths: most Arabs worshipped many gods, alongside Jewish, Christian and Zoroastrian communities. Into this world, in the city of Mecca, home of the Kaaba shrine, the Prophet Muhammad of the Quraysh tribe began preaching around 610 CE.
BattlesConstantinople, besieged 626 · Jerusalem, taken by Persia 614
Muhammad's followers were few at first, and for some 13 years Mecca's polytheist elite persecuted them; in 615 some fled across the Red Sea to Christian Aksum. In 622 they migrated to Yathrib, later called Medina; this Hijra marks the first year of the Islamic calendar. In Medina he united the tribes under a compact known as the Constitution of Medina and led his community in war against Mecca: at Badr in March 624 about 313 Muslims beat a Meccan force of 600 to 1,000. In 630 he marched on Mecca with 10,000 men and took it with few casualties, destroying the idols around the Kaaba. When he died in June 632, most of Arabia had embraced Islam.
After Muhammad's death in 632, his companion Abu Bakr became the first caliph, or successor, and in the Ridda wars forced rebel tribes back under Medina's rule. The first four 'Rightly Guided' caliphs then led a stunning expansion. In August 636 Arab armies crushed the Byzantines at the Yarmouk, and that November routed the Sasanians at Qadisiyyah, opening Iraq and Ctesiphon. Jerusalem surrendered to the caliph Umar in 637 or 638, and Amr ibn al-As conquered Egypt between 639 and 642. Within a decade Syria, Egypt and Iraq were taken. Victory at Nahavand in 642 broke Persian resistance, and by 651 the Sasanian Empire had been destroyed entirely: one of the most rapid conquests in history.
In 656 rebels killed the third caliph, Uthman, and Muhammad's cousin and son-in-law Ali succeeded him, igniting the first Muslim civil war, the First Fitna. Ali won the Battle of the Camel that December, but Uthman's kinsman Mu'awiya, governor of Syria, refused to recognise him; their clash at Siffin in July 657 ended in stalemate and arbitration. In 661 a Kharijite assassin killed Ali at prayer in Kufa, and Mu'awiya founded the Umayyad dynasty at Damascus, making the caliphate hereditary by naming his son Yazid heir. When Ali's son Husayn refused to accept Yazid, he and most of his family were killed at Karbala on 10 October 680. Shia Muslims mourn him every year at Ashura.
The Umayyad Caliphate, ruling from Damascus, pushed the frontier from the Atlantic coast of Morocco to the Indus valley. In 711 Tariq ibn Ziyad crossed from North Africa into Iberia with about 1,700 men and defeated the Visigothic king Roderic at Guadalete that July; most of the peninsula soon fell. That same year Muhammad ibn al-Qasim invaded Sindh, while in Central Asia Qutayba ibn Muslim took Bukhara and Samarkand. There were limits: a great siege of Constantinople failed in 717–718, and in October 732, after raiders had reached central France, Charles Martel's Franks defeated an Umayyad army between Tours and Poitiers. Covering perhaps 11 to 15 million square kilometres, it was among the largest empires that had ever existed.
In 750 the Abbasids, descendants of Muhammad's uncle al-Abbas, overthrew the Umayyads after a revolt that began in Khurasan in the east. Marwan II was beaten on the Great Zab river that January, and most of the Umayyad family was slain. In 751 Abbasid forces defeated a Tang Chinese army at Talas in Central Asia. In 762 the caliph al-Mansur founded a new capital at Baghdad, on the Tigris, around a walled Round City. Under Harun al-Rashid and his son al-Ma'mun, the House of Wisdom gathered Greek, Persian and Indian learning, much of it translated into Arabic; scholars such as al-Khwarizmi advanced algebra, medicine and astronomy. For centuries Baghdad was among the richest and most learned cities on earth.
No empire so vast could stay united. After a civil war between Harun's sons, caliphs came to rely on Turkic slave soldiers and in 836 moved their court to a new capital, Samarra. Local dynasties such as the Aghlabids in Tunisia, the Tulunids in Egypt and the Samanids in Central Asia ruled provinces in the caliph's name. By the 10th century rival caliphates had emerged: the Shia Fatimids proclaimed one in North Africa in 909 and later conquered Egypt, building Cairo, while Abd al-Rahman III revived the Umayyad line as caliph at Córdoba in 929. In 945 the Buyids, warlords from Iran, seized Baghdad itself. The unity of the early conquests gave way to a rich, plural Islamic world.
New powers ruled in the caliph's name. In 1055 the Seljuk Turks, Sunni Muslims from Central Asia, entered Baghdad at the caliph's invitation and ended Buyid rule there under their sultan, Tughril. At Manzikert in August 1071 Sultan Alp Arslan defeated and captured the Byzantine emperor Romanos IV, opening Anatolia to Turkish settlement. Byzantium's appeal for help led Pope Urban II to preach the First Crusade in 1095, and on 15 July 1099 crusaders took Jerusalem from the Fatimids, killing an estimated 3,000 to 10,000 Muslims and Jews. Saladin, a Sunni ruler of Kurdish origin, abolished the Fatimid caliphate in 1171, realigning Egypt with Baghdad, and in 1187, after his victory at Hattin, recaptured Jerusalem.
The Abbasid caliphate endured until 1258. When the caliph al-Musta'sim refused to send troops, the Mongol prince Hulagu Khan led a huge army against Baghdad. The siege began in late January; the caliph surrendered on 10 February, and the sack began three days later. The Mongols executed the last caliph; Hulagu later put the dead at around 200,000. Christians, for whom his Christian wife Doquz Khatun had pleaded, were spared. In 1260 the Mamluks of Egypt halted the Mongols at Ain Jalut. Figurehead Abbasid caliphs lived on in Mamluk Cairo until 1517, but its political power was over. But the religion, law, science and art it had nurtured would shape civilisations from West Africa to Southeast Asia.