The Hagia Sophia reflects the complex layerings of Christian and Islamic traditions.
The Hagia Sophia reflects the complex layerings of Christian and Islamic traditions.

While the western half of the Roman Empire disintegrated during the fifth century A.D., the eastern part of the Roman Empire -- commonly referred to as Byzantium or the Byzantine Empire -- flourished for another 10 centuries. As Byzantium faced ongoing territorial clashes with Islamic caliphates, a rich cultural cross-fertilization took place between Muslims and Orthodox Christians, as Islamic culture integrated Judeo-Christian forms of worship and preserved ancient Greek texts vis-a-vis Arabic translations.

Multiculturalism in the Byzantine Empire

As an expanding territory, the Byzantine Empire survived by evolving and incorporating different cultural and social elements. It was home to not only Orthodox and Coptic Christians, but also Syriac Christians and Jews. The region also supported heavy commerce and trade, which encouraged the dispersal and circulation of a wide range of texts, ideas and images. As an important religious region for Christians and Muslims, devoted followers traveled thousands of miles to pilgrimage centers in present-day Syria, Israel and the Palestinian territories, and Jordan. This fluid nature of intellectual and religious exchange helped pave the way for knowledge and different customs to be accepted, and in some cases, amalgamated by both Muslims and Christians living in the southern Byzantine territories.

Arab-Byzantine Wars

The rise of Islam in the Arabian Peninsula during the first half of the seventh century catalyzed a series of successful military campaigns by Muslim forces, as armies of Islamic caliphates captured present-day Lebanon, most of Syria, Israel and Jordan. In the new Islamic capital of Damascus, the remarkable Great Mosque of the Umayyads built during the eighth century reflected the rise of this new regional power. The military struggles between Byzantine and Islamic forces temporarily plateaued in 717 A.D., when the Muslim army of Caliph Umar II failed to capture Constantinople. As a result, a more stable relationship was established between the Abbasid Caliphate and Byzantium, although tensions remained up through the eventual collapse of Constantinople in 1453.

The Quran

The Quran, the central text of Islam, originated as an oral recitation and became a written text during the rule of the Umayyad Caliphate; the oldest written copy of the Quran dates back to the ninth century. As images of the prophet Muhammad were banned, the replication of excerpts from the Quran became important religious symbols that were engraved on buildings, mosaics and mosques throughout the expanding Islamic empire, including in the once important Byzantine territories of Syria and Egypt, which were conquered by Muslim forces during the seventh century.

Exchange of Knowledge

Starting from the seventh century, knowledge began to be readily exchanged between Muslim and Orthodox Christian intellectuals in what is now the Middle East and regions surrounding the Mediterranean Sea. The Islamic Empire, unlike the Germanic conquerers of the Western Roman Empire, incorporated and expanded upon Byzantine, Persian and Hellenistic knowledge. Arabic translations conserved important works by Aristotle, Plato and other ancient Greek philosophers, as many valuable texts had been destroyed by invading Germanic tribes in the west. In addition, knowledge was exchanged in the sciences and mathematics, as well as in medicine and philosophy. Important Arab intellectuals such as Ibn Sina, known to Europeans by the Latinized name “Avicenna,” also sought to integrate aspects of Greek philosophy into Islamic theology.

Conquest of Constantinople

Following the Macedonian dynasty, the Byzantine Empire began to deterioriate as inner strife and competing interests intensified between the ruling aristocracy and the empire's administration. Additionally, invasions from both the east and west persistently threatened the empire: Norman forces in Italy clashed with Byzantine forces in the west, while Turks began their invasions of Asia Minor in the east. Internal divisions, an official break from the Roman Catholic Church, ongoing defeats by Turkish forces and the encroaching invasions of the Mongol Empire under the great leader, Genghis Khan, were all critical factors that weakened the Byzantine Empire. The military victories of Genghis Khan also threatened the Islamic Abbasid caliphate, and the last Abbasid caliph was executed in 1258. Two centuries later, a fragile Byzantine Empire was defeated by the Ottoman Empire.