HIS101 logo The Byzantine Empire and Islam
by Jim Jones, West Chester University of Pennsylvania (c.2003)
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If history can be said to tell the story of Europe's triumph over all of the rest of the world, then the Byzantine Empire played a significant role in Europe's victory. At first, the Byzantine Empire was an ally of the West, although later it became an adversary. In both cases, the Byzantine Empire stood as a bulwark against Eastern expansion - first Persian and later Moslem.

The Byzantine Empire was the name applied to what remained of the eastern Roman Empire after 450AD. It was centered around the eastern end of the Mediterranean , and located between the Nile Valley, the southern shore of the Black Sea, and inland as far as Mesopotamia. The principal city of the Byzantine Empire was the former eastern capital, Constantinople.

The Byzantine Empire was surrounded by enemies. It was due west of the powerful Persian empire that revived in Parthia following the Roman retreat. The Byzantine Empire also faced a challenge from European barbarians in the West. The central Asian nomads that challenged the Western Roman Empire also offered a constant threat. Finally, because the Byzantine Empire was located between Black and Mediterranean Seas, it was a major naval power .

The basic concern of emperors in both Rome and Constantinople was how to maintain the empire . Once Rome was sacked in the fifth century AD, their concern switched to "how to reconstruct the empire." That presented two practical problems: how to raise an army, and how to organize a system of administration. The answers to both problems required men, wealth and imperial unity.

In the Byzantine Empire, the Christian Church became a tool for solving both problems. The Church controlled great wealth through the system of tithes, which required each Christian to donate one tenth of his earnings to the Church to pay for good works. Later, Christianity also provided a sense of unity of purpose for recolonizing the western Roman Empire in the name of Christianity. Especially during the Crusades, Christian leaders were able to mobilize large armies in defense of their religion.

Spiritual and political (physical) power: This quotation provided the basis for the Christian Church's acquisition of wealth, and with that, political power.

Thus speak unto the Levites, and say unto them, When ye take of the children of Israel the tithes which I have given you from them for your inheritance, then ye shall offer up an heave offering of it for the LORD, even a tenth part of the tithe. (Numbers 18: 26)


At first, Constantinople and Rome cooperated because the Roman bishops relied on the Byzantine emperors for military assistance against the barbarians. For instance, the Emperor Justinian invaded the Italian peninsula in 527AD and reconquered Italy, the Balkans, and Numidia. The Roman bishops also received large amounts of money from Christians until eventually, Rome became the richest of the Five Holy Sees (Rome, Constantinople, Antioch, Alexandria, Jerusalem).

Theological dispute over leadership: However, as Christianity spread among the barbarians who settled in Europe, rivalry developed between the two imperial cities of Rome and Constantinople. The Roman bishops claimed leadership over Christianity based on the Gospel verse in which Jesus tells Peter (first bishop of Rome) that you are the rock on which I will build my church (Matthew 16: 18-19). Byzantine Emperors based their claims for leadership on the succession of leadership within the Christian Roman Empire.

Practical dispute over leadership: The Byzantine Emperor controlled the largest population of Christians, access to Christian holy sites, and the wealthiest part of the empire. However, the Roman bishopric obtained extra prestige after the reign of Victor around 190, who behaved responsibly during the last years of Commodius' reign (following the last of the Five Good Emperors). Also, by the 4th-5th centuries, the Roman bishops directed the most dynamic part of the Christian world--barbarian Europe--where missionary activity attracted the most energetic Christians and donations for the good work of converting barbarians.

The Byzantine Emperor imposed an imperial bureaucracy on the practice of Christianity by using bishops as inspectors and by calling conferences to codify doctrine. The first world council of Christianity was held at Nicaea 325AD. The Byzantine Emperor also recognized five Christian patriarchs in Jerusalem, Alexandria, Antioch, Constantinople, and Rome, but only Rome was in the western Roman Empire. These became known as the five Holy Sees.


The Iconoclastic Controversy of 710AD completed the break between Rome and Constantinople. The Controversy began under Emperor Leo the Isaurian, the emperor who defended Constantinople against the Arabs in 717. Facing numerous defections to the Muslims along his southern border, and the creation of a Muslim Persia along his eastern border, Emperor Leo initiated religious reforms in an attempt to retain followers.

Although these reforms were extensive, the main item was a declaration that religious images were corrupt. This appealed to Eastern Monophysites who refused to accept Jesus' divinity, and to Muslims who distrusted the worship of anything that came between the individual and the deity (saints), but it also resulted in the destruction of much Byzantine religious art.

The Byzantine reforms had political goals as well as spiritual goals. By purifying Christianity, they hoped to reduce the attractiveness of Islam to Eastern Monophysites and other religious opponents. By eliminating religious images, they hoped to undermine the worship of saints, including that of St. Peter, who was the ancestral founder of the Roman bishopric. Finally, by doing away with the worship of saints, the emperor also found a reason to close monasteries and confiscate their wealth for the Empire.

Byzantine missionaries penetrated Russia along the rivers that flow north out of the Black Sea. As they spread out, Byzantine missionaries converted the Kievian Varangian rulers of the Slavs, and spread the Greek language and the Roman imperial system . Later, the Mongol invasions forced the withdrawal of Russian Orthodox Christians to the north around Moscow , where a new empire, linked to but distinct from the Byzantine Empire, became a powerful influence on the Baltic region and northeastern Europe. In modern times, the leaders of Russia were known as Tsars, which is derived from the Roman title of Caesar.


Islam is one of the world's popular religions, and one that appears regularly in world news. As of 1992, Islam had the second largest number of followers (935 million) in the world after Roman Catholicism.

Islam was founded in the Arabia Desert south of Mesopotamia in the early 7th century. Theologically, Islam is the third religion based on Middle Eastern monotheism. In each religion, a prophet revealed additional information about the will of the supreme metaphysical power. The first prophet was Moses, who founded the religion of Yahweh (Judaism) about 1200-1100BCE. The second was Jesus, who teachings provided the basis for Christianity in 30-33CE. The third was Mohammed, who laid the groundwork for Islam.


Islam developed in the Arabian Desert, in towns called Mecca and Medina. Both Mecca and Medina were towns on a caravan route that ran parallel to the Red Sea coast. Control over this area was disputed between the Byzantine empire and the Persians . After the traditional sea trading routes were disrupted by naval conflict between the two powers , the alternate land route made Mecca prosperous.

Mecca was already an important religious site prior to the development of Islam. The region around Mecca was populated by nomadic Arabs who worshipped their own local gods, and Mecca was home to a religious site called the Kabaa . Local priests dominated the government of Mecca, thanks to the wealth they accumulated from offerings to the Kabaa.

Muhammed was a member of a prosperous trading family at the time when trade through Mecca was very profitable. He married well at age 25 to Khadijah, an older, wealthy widow. He became successful at trade himself. However, Muhammed spend some of his time as a hermit in contemplation at a cave on Mt. Hira, near Mecca.

In 610AD, Muhammed began to claim that he received messages from the deity. When Muhammed began to spread "god's word" to what he called barbarian Arabs, he acquired enemies in Mecca and was forced to leave in 622, on a journey that became part of Muslim history as the hijira. Muhammed went to Yathrib, about 200 miles away, where he was welcomed because he proved successful at settling disputes between different ethnic groups. Later, the name of the town changed to Medina because Muhammed stayed there.

Unlike Mecca, Medina was a cosmopolitan trading city. Medina was composed of camps populated by people from different ethnic groups who came there to trade. Consequently, Medina experienced a lot of internal unrest as a result of the ethnic divisions.

As Muhammed's influence grew, he led his followers on raids against caravans from Mecca, and after an army from Medina defeated Mecca in 630, he was able to return to his home town in 632. Unfortunately, Muhammed died only three months later, leaving no male heir.


The characteristics of Islam: Islam is a strict monotheism. The basic statement of Islamic faith is: "There is no god but Allah, and Muhammed is his prophet." Muhammed rejected Christianity as a polytheism because Christians worshipped both God and Jesus. However, Allah told Muhammed to accept Jews and Christians as "people of the book" because they accepted the Old Testament . Muhammed's role was to simply to remove corruption from Christianity and Judaism.

Compared to Christianity, Islam was a simple religion. Islam has no official clergy , although some people learn more about Muhammed's teaching than others. Islam follows a single sacred text, the Koran of Allah's word, although it also accepts the validity of the Old Testament.

The basic beliefs of Islam are called the Five pillars of Islam First, there is the Shahada, which requires believers to recognize Allah as the supreme deity . Believers must also make five daily prayers to Mecca . Believers must give charity , such as alms to the poor. They must also fast during the month of Ramadan . Finally, every Muslim must visit Mecca at least once on a trip known as the hajj . Although it was not required by Allah, there is a potential sixth pillar, jihad, which refers to efforts made to convert others to Islam.

Islam was more than a religion; it was guide to life. The Shari'a, which combined elements from the Koran, Muhammed's life and assorted legal precedents, was the basis for Islamic law. The Shari'a contained more than just criminal law, and included complex code of ethics. For instance, the offenses of wine-drinking and lying (bearing false witness) were each punishable by 80 lashes because both led to distortions of reality (drunkenness leads to hallucinations).

Although the Muslim treatment of women may seem barbaric by modern Western standards, it was progressive by the standards of the 7th century. According to the Shari'a, a husband must support his wife, and was limited to a total of four wives. The Shari'a also provided a formal means of divorce, which allowed a woman to escape a brutal husband, at least in theory.


Muhammed died without naming his successor and a struggle for the control of Islam ensued. Muhammed had already introduced the idea of the ulema or council of religious scholars to interpret law, and they took charge of deciding who was entitled to become the next leader of Islam. Abu Bakr (Nohammed's best friend and father-in-law of Muhammed's second wife) won, but Muhammed's son-in-law Omar (Umar; married to Fatima) fought back. Abu Bakr took the title caliph, meaning "leader, successor and deputy" (of Muhammed), and supported his authority by unleashing a jihad against the mon-Moslems to the north in the Byzantine and Persian empires.

Abu Bakr died shortly thereafter in 634, and the ulema chose Umar to take over as leader of Islam. But Umar was assassinated in 644, so Uthman, a member of the powerful Ummayyid family was selected as the new caliph. After Uthman was assassinated in 656, his cousin Ali took over, but faced accusations of having assassinated his cousin. Ali was assassinated himself in 661.

Yazid (680-682), the son of Mu'awiya (661-680), was theoretically selected by the ulema, but was actually chosen thanks to pressure exerted by his father. He restored stability, consolidated Ummayyid rule, and became the first hereditary caliph. However, divisions developed as a result, and the Sunni became the majority group who accepted the control of the Ummayyids. The Shi'ite were a minority group who believed that Muhammed Ali, cousin and son-in- law of Muhammed (husband of Fatima), had transmitted Allah's words most accurately and was entitled to hold the office of Caliph of Islam.

A third approach to Islam was Sufiism, which emphasized a more mystical approach to Allah that was rejected by both Sunni and Shi'ite Muslims. They worshiped Muslim saints (Awliya), which made more orthodox Muslims suspect them of polytheism. Other small heresies existed, such as the puritanical Wahhabis (Saudi Arabia), the Druze (Lebanon) and the Alawi (Shi'ite) sect.


The expansion of Islam: Muslim forces had quick and extensive military success. In 636, Damascus fell to Arabs, and in 638, Jerusalem fell. In 639, the Byzantine fortress of Babylon (Cairo) fell, and in 640, Alexandria fell under Muslim control. Meanwhile, Muslim expansion to the north resulted in the total defeat of Persia by 651AD.

After Umar was assassinated in 644, the Ummayyid family founded a dynasty that lasted until 750AD. The Ummayyids directed the Muslim advance along the North Africa coast after 600. The Ummayyids also developed a navy to combat the Byzantine navy in the Mediterranean, and eventually established their capital in Damascus in order to avoid the influence of the religious leaders in Mecca.

The first Ummayyid attack against Tunisia succeeded by 670AD, and they established their main base at Kairawan (near the coast, but inland, and south of Tunis). This location was safe from water-born Christian Byzantines, and safe from inland Berbers of mountain and desert. By 720, the Ummayyids controlled everything south of Pyrenees, but in 732, they were defeated at Poitiers by a Frankish military leader (mayor of the palace), Charles Martel.

After 750AD, the Ummayyids were overthrown by the more eastern-oriented Abbassids. They moved the capital from Damascus to Baghdad , and as a result, Muslim expansion slowed in northern Africa. Instead, Islam began to expand down the East Africa coast and across into Asia.

However, unlike the Ummayyid Muslim world, the Abbassid Muslim empire was fragmented. An independent Ummayyid leader remained in control in Cordoba (Spain), and independent emirs ruled in Tunisia and Khorasan. Buyyid Shi'ites conquered Baghdad in 945, but retained the Abbassid caliph as a puppet. By 969, the Tunisian-based Fatimid movement had conquered Abbassid holdings in Egypt and established a new capital at Cairo.

The puppet Abbassid caliphs attempted to use Seljuk Turks to regain power, but instead, the Seljuks took over in Baghdad in 1055 by "confirming" the ulema's choice of Caliph. Seljuks introduced the office of Sultan, meaning "he with authority." After the Mongol invasion in the 13th century, the Turkish Seljuks took control of the Muslim Caliph's army.

Ultimately, a rival Turkish Muslim group, the descendants of a military leader named Othman, established control in the area nearest the Byzantine Empire, and gradually whittled away at Byzantine territory. In 1453, descendants of Othman (Ottomans) conquered Constantinople .

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