The Spread of Islam along the Silk Road

Islam was the last of the great universal religions to spread along the Silk Road, and the one that eventually came to dominate. Within roughly four centuries of the death of the Prophet Muhammad in 632, Islam had traveled from Arabia to the Atlantic in the west and to the borders of China in the east, and had become the majority religion of the entire central corridor of the overland Silk Road, from Baghdad to Samarkand and beyond. The conversion of Central Asia was one of the great religious transformations of the medieval world, and the new Islamic civilization that resulted was, for several centuries, the political, economic, and intellectual center of the Silk Road. The standard textbook version of this story is a military one, with the Arab armies doing the converting; in my view the trade and the Sufi missions did more of the actual work, and on a longer timescale.

The story belongs to the larger history of religions of the Silk Road, but it has a special character. Where Buddhism had been carried into Central Asia by monks, and Christianity by missionary priests, Islam was carried by both armies and merchants, and it was supported, in many cases, by the political structures of the new Arab and Turkic dynasties. The spread of Islam was thus a process that combined conquest, conversion, and the long, slow influence of trade and Sufi missionary activity. A point that is often missed: the populations that converted were not the same populations the Arabs conquered, and the religion they ended up with was not the religion the conquerors brought.

The Arab conquests

636 CE. The Battle of al-Qadisiyyah. Twelve years after the Prophet’s death, the Sasanian Empire is effectively over.

Within a generation of the death of the Prophet, Arab armies had taken the Sasanian Persian Empire, the Levant, Egypt, and much of North Africa. The conquest of Persia in the 640s and 650s brought the Arab caliphate to the eastern frontier of the Sasanian state, and from there the Arabs pushed into the oasis cities of Khorasan and Transoxiana. The conquest of Bukhara and Samarkand in the early eighth century opened the heart of Central Asia to Muslim rule, and the Battle of Talas in 751 CE, in which Arab forces defeated a Tang Chinese army near the Syr Darya, established Muslim control of the eastern Silk Road.

The Arab conquests were not, in the first instance, religious missions. They were imperial expansions driven by the political, economic, and religious logic of the new caliphate, but the religious consequences were profound. The establishment of Arab garrisons, the foundation of mosques and madrasas, and the imposition of Islamic law created the institutional infrastructure within which the slow process of conversion took place. The Samanid dynasty, which ruled Khurasan and Transoxiana from Bukhara in the ninth and tenth centuries, was the first native Iranian Muslim dynasty, and under the Samanids Bukhara became the center of a Persian literary renaissance that laid the foundations for the great Persian literary tradition. The more I read the Samanid sources, the more I think the Samanid court is the under-acknowledged pivot of the whole period; the Abbasids got the press, the Samanids did the work.

Islam is, of the five religions, the one with the most lasting political consequences.

The conversion of the Turks

The first Turkic conversions were political acts, not mass religious movements.

The conversion of the Turkic nomads of the Central Asian steppe was a slower and more complex process than the conversion of the sedentary populations of the oases. The first Turkic peoples to convert were the Karakhanids, a confederation of Turkic tribes that ruled the region of Kashgar and the western Tarim Basin in the tenth century. The Karakhanid ruler Satuq Bughra Khan converted to Islam around 934 CE, and the conversion of the Karakhanid ruling class was followed, over the next century or two, by the conversion of the bulk of the Turkic population of the Tarim Basin. (The Satuq Bughra Khan mausoleum at Artush, about 30 km from Kashgar, is the principal modern pilgrimage site for the Karakhanid conversion; it was substantially rebuilt in the 1990s and is not what it was in the 1950s.)

The Karakhanid conversion had two major consequences. The first was the destruction of the last great Buddhist kingdom of the Tarim, the kingdom of Khotan, which fell to the Muslim Karakhanids in the early eleventh century. The fall of Khotan ended Buddhist civilization in the Tarim Basin and led, almost certainly, to the sealing of the Library Cave at Dunhuang in roughly the same period. The second was the establishment of Islam as the religion of the western Tarim, where it has remained into the present. Popular accounts tend to treat the Khotan fall as a single decisive event; I think it was at least two events (the Karakhanid advance and the sealing of the cave) that happened to coincide within a generation.

A personal note

I have used “Islam” throughout, but the conversion of Central Asia was not a single event. The first conversions were to (Shi’a) forms of Islam, the later conversions to (Sunni) forms, and the Sufi orders brought yet a third set of practices. The reader looking for a single conversion story will not find it. There were at least three distinct conversions of Central Asia, spread over four centuries, and the populations that converted were not identical.

Further reading

If you only have time for one thing, read Hansen (2012) — the rest is detail.

• Hansen, The Silk Road: A New History (Oxford, 2012).
• Peter Frankopan, The Silk Roads (Bloomsbury, 2015), if you want the more sweeping argument.
• Whitfield, Life Along the Silk Road, 2nd ed. (2015).
• The relevant chapter of the Oxford Handbook or Cambridge History of the region or period.
• One article from a recent issue of Central Asiatic Journal or Journal of the Economic and Social History of the Orient (JESHO) for current scholarship.

Related pages

See also Religions of the Silk Road, The Islamic Golden Age and the Silk Road, and Baghdad and the Silk Road.