• Towards the end of the Abbasid caliphate, the formerly vast and united Islamic empire became fragmented and decentralized.
  • Many different groups ruled areas previously held by the Abbasids.
  • Religious institutions became more defined during this period as state power waned.
  • Trade contributed to the spread of Islamic culture and led to a growing feeling of internationalism.
From the ninth century to the twelfth century, Islamic culture flourished and crystallized into what we now recognize as Islam. The military expansions of the earlier period spread Islam in name only; it was later that Islamic culture truly spread, with people converting to Islam in large numbers.
This spread of Islamic culture was facilitated by trade, missionaries, and changes in the political structure of Islamic society. As a result, we encounter multiple different interpretations of Islam across many different Islamic societies.

Political decentralization and fragmentation

The Abbasids’ massive empire—spanning over four thousand miles—was impressive, but very difficult to maintain. As people converted to Islam, tax revenue collected from non-Muslim subjects dwindled, and the Abbasid court could no longer sustain its expenditures. Abbasid religious authority was also wavering as a more powerful class of religious scholars at the helm of new religious institutions challenged the legitimacy of the system of caliphate.
Ultimately, the highly centralized Abbasid caliphate fragmented into multiple smaller, independent political structures. These new political structures diminished Abbasid power.
It was perhaps this political decentralization and destabilization that led to the spread of Islam beyond the massive Abbasid empire’s borders. Regional rulers, who did not have to manage such vast territories, were able to expand more fruitfully in single directions. For example, the Fatimids and Berber dynasties in North Africa were able to expand into Sub-Saharan Africa, and the Ghaznavids stretched farther into India.
How did the Abbasid empire change over time?
How did these changes contribute to the spread of Islam?

The formation of diverse religious and state institutions

Modern Islam is divided into many sects. While the tensions that led to the development of these sects were certainly present in the early history of Islam, it took centuries for different religious interpretations to become organized into clear schools of thought. As scholars compiled histories, laws, and philosophical treatises, the main schools of legal thought emerged.
A page with Arabic handwriting in ink.
A page from a manuscript on Islamic law from Spain, first half of the 11th century. Image credit: Wikimedia Commons.
Just as religious institutions were gaining stability, political establishments were becoming even more unstable. As Muslim Turks migrated into the Islamic empires, other groups invaded, including the Mongols. Another source of political instability was the confrontation between Muslims and Christians in Western Europe, with the inquisition, the Crusades.
In the shadow of these political upheavals, Islamic political structures transformed, and new leaders from beyond the traditional Arab Muslim elite emerged. Kurdish leaders, like Saladin of the Ayyubid dynasty, were incredibly influential. Mamluk slave-soldiers of Turkish origin were also gaining power.
A drawing showing a man practicing with a lance, a long weapon with a wooden shaft and a pointed steel head, formerly used by a horseman in charging. The man has a beard and wears a red garment on his head. There is text in the Arabic script around the drawing.
A depiction of a Mamluk training with a lance in the early 16th century. Image credit: Wikimedia Commons.
Eventually, multiple small states emerged where the Abbasids once ruled exclusively. The Abbasids’ five-century existence finally came to an end with the Mongol sacking of Baghdad in 1258.
A painting depicting a battle. Warriors are crossing water and land, charging a fortified area,.
A painting depicting the siege of Baghdad by the Mongols in 1258. Image credit: Wikimedia Commons.
After the fall of the Abbasids, alternative social and political structures filled the vacuum. Sufi religious institutions were one such alternative structure. Sufi missionaries were responsible for many conversions in sub-Saharan Africa and in South and Southeast Asia.
Conversion from other religions like Christianity and Judaism was relatively easy and quick due to shared religious ideas. Conversion from pagan and polytheistic religions, however, was more difficult. Sufi missionaries navigated these difficulties adeptly, making Islam appealing by assimilating it into existing religious traditions.
This assimilation is evident in the mix of Islamic traditions with pre-Islamic belief systems in syncretic religious systems. For example, Kebatinan, a religion that appeared in modern-day Indonesia around the sixteenth century combined animistic, Buddhist, Hindu, and Islamic—especially Sufi—beliefs and practices.
Four small objects with inscriptions in Arabic letters.
A kebatinan talisman, which is meant to increase spiritual power. Image credit: Flickr (CC BY 2.0).
By the late Abbasid period, Muslim rule was no longer an Arab phenomenon. Muslim Kurdish, Persian, Turkish, Mongol, and Afghan leaders secured power in places as far apart as modern-day Turkey and modern-day northern India. From there, Islam spread to modern-day Malaysia and Indonesia.
Indeed, it was the later Persian Safavid and Turkish Ottoman empires, neither of which was Arab, out of which the modern Islamic world was carved.
How did the ethnic character of the Muslim Empires change over the course of the Abbasid caliphate?
What is one of the ways that syncretic Islamic traditions emerged?
Missionaries and political expansion moved Islamic culture, but Islamic culture also traveled through trade. Caravans, groups of travelers who used camels to transport themselves and goods across land, were critical to the spread of Islam. Just as camels enabled the first caliphs to expand their empires, caravans allowed the Abbasids and other powers to expand their civilizations and enrich their cultures by linking provinces which were far from one another. Advanced road networks enabled caravans filled with soldiers, pilgrims, envoys, merchants, and scholars to travel across vast territories.
Along these trade routes, merchant communities developed. Muslims controlled parts of the western silk road and were influential on trans-Saharan trade routes. They also were powerful entities in maritime trade in the Red Sea, Persian Gulf, and Indian Ocean.
A drawing of a group of people traveling on horseback in a straight line.
A depiction of a caravan traveling along the Silk Road around the fourteenth century. Image credit: Wikimedia Commons.
While these trade interactions undoubtedly had important ramifications, they were equally influential in the cultural realm. They created a sense of internationalism and multiculturalism. This cultural exchange seems obvious to our modern sensibilities, but at the time, it was an entirely new way of thinking about the world.
New cultural relationships resulted in the transfer of technology, science, and other cultural forms. For example, interaction between Arab Muslim forces and the Tang dynasty may have resulted in the exchange of the technology of paper, which revolutionized the Muslim world and later traveled to Europe.
How did trade interactions result in cultural exchange?
Article written by Eman M. Elshaikh
Berkey, Jonathan. The Formation of Islam: Religion and Society in the Near East, 600-1800. Cambridge: Cambridge University Press, 2003.
Hoyland, Robert G. In God's Path: the Arab Conquests and the Creation of an Islamic Empire. Oxford: Oxford University Press, 2015.
Lapidus, Ira M. A History of Islamic Societies. New York: Cambridge University Press, 2014.
Silverstein, Adam J. Islamic History: a Very Short Introduction. Oxford: Oxford University Press, 2010.