After the fall of Rome, three civilizations emerged that were based on religion.  This chapter discusses two of these—Byzantium and Islam—and their cultural contributions to Western civilization.

As barbarian invaders dismantled the western empire, the East survived as Byzantium with Constantinople as its capital.  While trade, urban life, and learning declined in the West, Byzantium developed a vital economy, sophisticated intellectual and artistic life, and a strong government that supported the Eastern church.  Doctrinal and administrative differences caused the Western and Eastern churches to split in 1054, concluding a centuries-long division between Latin and Greek Christendom.  Byzantium reached its political height under Justinian, who reconquered parts of the old western empire.  Successive attacks from a variety of peoples, including Latin Christians, weakened Byzantium, which finally fell to the Ottoman Turks in 1454.

Byzantium preserved important elements of the Greco-Roman tradition.  Under Justinian's direction, Byzantine scholars collected and codified Roman law in the four-part Corpus Juris Civilis.  Influenced by Greek historians, Byzantines including Procopius, Michael Psellus, and Anna Comnena offered rational, coherent, if not always objective, accounts of historical events.  Byzantine religious thinkers studied Greek philosophy but subordinated philosophical activity to the enterprise of theology.

Byzantium developed a rich musical, artistic, and architectural tradition.  Drawing from Greco-Roman and Hebrew theory and practice, Byzantine musicians created a tonal system that influenced the course of Western music, and Kontakion hymnody derived from early Christian models.  Byzantine art mainly concerned itself with glorifying the empire and serving religious purposes.  The iconoclastic controversy forced artists to find new ways of approaching the problem of representing the human form, but even so, Byzantine artists never explored realism as deeply as their Western counterparts did.  Ravenna became the center of much early artistic activity.  Buildings such as Galla Placidia's mausoleum, Theodoric's church of Saint Apollinare, and San Vitale represent variations on both the basilica and centralized plans and include notable paintings or mosaics depicting Christian themes.  San Vitale also includes mosaics glorifying Justinian and Theodora, and Saint Apollinare in Classe contains an important representation of Christ Pantocrator.  The greatest Byzantine monument is Justinian's reconstructed Hagia Sophia, a unique blend of the basilica and centralized styles that Ottoman conquerors transformed into a mosque.

As Byzantium flourished, Islam emerged from the Arabia.  Based on the religious experience of the prophet Muhammad, Islam grew in opposition to earlier Arab polytheism and to Judaism and Christianity.  After a period of persecution, Muhammad and his followers conquered Arabia with the help of Bedouin converts.  After Muhammad's death, the newly unified Muslim Arabs launched a jihad, ultimately conquering an empire that stretched from Spain to India.  Integrated many cultural traditions, Muslim civilization reached its height under the Abbasid caliphs who ruled from Baghdad.  Waves of invaders from Central Asia weakened the Arab empire until it fell to the Ottoman Turks, whose armies pushed far into Eastern Europe.

A monotheistic religion, Islam presented itself as the fulfillment of Judaism and Christianity.  Though not considered divine, Muhammad was regarded as the last, greatest prophet in a line that included Abraham and Jesus.  His teachings on the Five Pillars of the faith and on a variety of practical questions are compiled in the Qur'an and Hadith.  Islam eventually broke into three majors sects: the Sunnites and Shi'ites, who divided over questions of leadership and orthodoxy, and the Sufis, who rejected rational speculation and instead cultivated mystical spiritual experience.  Sufism grew dramatically during the thirteenth-century Mongol invasions, as Muslims sought solace in the face of disaster.  The Islamic state was theocratic, in which rulers governed according to religious law.  Although the lot of Arab women improved with Islam, ambiguities in the Qur'an and Hadith led to the establishment of an Arab-style patriarchy in which women were entirely subordinate to men.  Islam accorded special status to Christians and Jews.  Although they endured restrictions and penalties as non-Muslims, these "Peoples of the Book" generally lived free of persecution.

Islamic thought also preserved the Hellenic tradition and helped pass it on to the West.  Muslim physicians, scientists, and mathematicians built upon the work of the Greeks, expanding their insights and often correcting their mistakes.  Islamic philosophers used Platonic and Aristotelian ideas to explore Muslim theological concerns.  Thinkers including Al-Farabi and Avicenna used Neoplatonic and Aristotelian concepts to prove the existence of God, while Averroës employed Aristotle to argue that philosophy and study of the Qur'an were compatible.  Ibn Khaldun contributed to historiography with his Universal History, which includes, along with a comprehensive account of civilization, an analytical autobiography.

Islamic literature and art displays a wide range of forms and thematic concerns.  The poet Ibn Hazm wrote a critical analysis of love.  Omar Khayyam's quatrains infused expressions of love with philosophical resignation, while Rumi explored Sufi mystical experience.  The popular Thousand and One Arabian Nights incorporated diverse tales within a unified frame story, employing hyperbole to evade the Muslim ban on fiction.  Working within the ban on images of living creatures, Islamic art emphasized abstract ornamental styles.  During the Umayyad and Abbasid dynasties, distinctive architectural styles emerged.  Based on Byzantine models, shrines such as the Dome of the Rock employed calligraphy to decorate the interiors and convey sacred messages.  A standard mosque plan also developed, focusing attention on the Qibla wall and later incorporating minarets for muezzin calls.  Among the most notable mosques are those of Damascus, Samarra, and Cordoba.  An important late work is the Alhambra, a palace-complex in Granada designed inside to create ethereal effects conducive to reflection.

Byzantine and Islamic civilization gave crucial legacies to the West.  Byzantine Orthodoxy shaped the religious traditions of much of Slavic Europe, and both civilizations helped to preserve and transmit important elements of the Hellenic tradition: Byzantium, the Roman legal tradition and modified Hellenic architectural styles; Islam, the scientific and philosophical tradition of Greece.  Contact with both civilizations enabled Latin Christendom to absorb the Hellenic legacy during the Middle Ages.