The Spread of Islam began shortly after the death of the Islamic prophet Muhammad in 632. Trade networks connected many religions which helped the spread of Islam. During his lifetime, the community of Muslims, the ummah, was established in the Arabian Peninsula by means of conversion to Islam. In the first centuries conversion to Islam followed the rapid growth of the Muslim world under the Rashidun and Umayyad Caliphs. Muslim dynasties were soon established and subsequent empires such as those of the Abbasids, Almoravids, Seljuk Turks, Mughals in India and Safavids in Persia and Ottomans were among the largest and most powerful in the world. The Islamic world was composed of numerous sophisticated centers of culture and science with far-reaching mercantile networks, travelers, scientists, astronomers, mathematicians, doctors and philosophers, all of whom contributed to the Golden Age of Islam. The activities of this quasi-political early ummah resulted in the spread of Islam as far from Mecca as China and Indonesia, the latter containing the world's largest Muslim population. Today there are between 1.1 billion and 1.8 billion Muslims, such that Islam the second-largest religion in the world.
In the first century the establishment of Islam upon the Arabian peninsula and the subsequent rapid expansion of the Arab Empire during the Muslim conquests, resulted in the formation of an empire surpassed by none before. For the subjects of this new empire, formerly subjects of the vanishing Byzantine and Sassanid Empire, not much changed in practice. The objective of the conquests was more than anything of a practical nature, as fertile land and water were scarce in the Arabian peninsula. A real Islamisation therefore only came about in the subsequent centuries.
Ira Lapidus distinguishes between two separate strands of converts of the time: one is animists and polytheists of tribal societies of the Arabian peninsula and the Fertile crescent; the other one is the monotheistic populations of the Middle Eastern agrarian and urbanized societies.
For the polytheistic and pagan societies, apart from the religious and spiritual reasons each individual may have had, conversion to Islam "represented the response of a tribal, pastoral population to the need for a larger framework for political and economic integration, a more stable state, and a more imaginative and encompassing moral vision to cope with the problems of a tumultuous society." In contrast, for sedentary and often already monotheistic societies, "Islam was substituted for a Byzantine or Sassanian political identity and for a Christian, Jewish or Zoroastrian religious affiliation." Conversion initially was neither required nor necessarily wished for: "(The Arab conquerors) did not require the conversion as much as the subordination of non-Muslim peoples. At the outset, they were hostile to conversions because new Muslims diluted the economic and status advantages of the Arabs."
Only in subsequent centuries, with the development of the religious doctrine of Islam and with that the understanding of the Muslim ummah, did mass conversion take place. The new understanding by the religious and political leadership in many cases led to a weakening or breakdown of the social and religious structures of parallel religious communities such as Christians and Jews.
The caliphs of the Umayyad dynasty established the first schools inside the empire, called madrasas, which taught the Arabic language and Islamic studies. They furthermore began the ambitious project of building mosques across the empire, many of which remain today as the most magnificent mosques in the Islamic world, such as the Umayyad Mosque in Damascus. At the end of the Umayyad period, less than 10% of the people in Iran, Iraq, Syria, Egypt, Tunisia and Spain were Muslim. Only on the Arabian peninsula were there substantially more Muslims among the population.
Expansion ceased and the central disciplines of Islamic philosophy, theology, law and mysticism became more widespread and the gradual conversions of the populations within the empire occurred. Significant conversions also occurred beyond the extents of the empire such as that of the Turkic tribes in Central Asia and peoples living in regions south of the Sahara in Africa through contact with Muslim traders active in the area and sufi missionaries. In Africa it spread along three routes, across the Sahara via trading towns such as Timbuktu, up the Nile Valley through the Sudan up to Uganda and across the Red Sea and down East Africa through settlements such as Mombasa and Zanzibar. These initial conversions were of a flexible nature and only later were the societies forcibly purged of their traditional influences.
The reasons why, by the end of the 10th century CE, a large part of the population had converted to Islam are diverse. One of the reasons may be that
"Islam had become more clearly defined, and the line between Muslims and non-Muslims more sharply drawn. Muslims now lived within an elaborated system of ritual, doctrine and law clearly different from those of non-Muslims. (...) The status of Christians, Jews and Zoroastrians was more precisely defined, and in some ways it was inferior. They were regarded as the 'People of the Book', those who possessed a revealed scripture, or 'People of the Covenant', with whom compacts of protection had been made. In general they were not forced to convert, but they suffered from restrictions. They paid a special tax; they were not supposed to wear certain colours; they could not marry Muslim women; their evidence was not accepted against that of Muslims in the law courts; their houses or places of worship could not be ostentatious; they were excluded from positions of power (although in various places Jews and Christians worked as secretaries or financial officials for Muslim rulers)."
It should be pointed out that most of these laws were elaborations of basic laws concerning non-Muslims (dhimmis) in the Quran. The Quran does not give much detail about the right conduct with non-Muslims, in principle recognizing the religions of the book and demanding a separate tax for them.
American historian Ira Lapidus points towards "interwoven terms of political and economic benefits and of a sophisticated culture and religion" as appealing to the masses. He writes that :
"The question of why people convert to Islam has always generated intense feeling. Earlier generations of European scholars believed that conversions to Islam were made at the point of the sword, and that conquered peoples were given the choice of conversion or death. It is now apparent that conversion by force, while not unknown in Muslim countries, was, in fact, rare. Muslim conquerors ordinarily wished to dominate rather than convert, and most conversions to Islam were voluntary. (...) In most cases worldly and spiritual motives for conversion blended together. Moreover, conversion to Islam did not necessarily imply a complete turning from an old to a totally new life. While it entailed the acceptance of new religious beliefs and membership in a new religious community, most converts retained a deep attachment to the cultures and communities from which they came."
The result of this, he points out, can be seen in the diversity of Muslim societies today, with varying manifestations and practices of Islam.
Contrary to Lapidus, anthropology professor Kamuyu-Wa-Kang'ethe points out that there are also examples of African societies (notably Egypt and Somalia) that had their ethnic heritage almost completely wiped out by the encroaching Muslims, due to prohibition against long-standing African cultural traditions in favor of foreign, Muslim beliefs, and the castration of African males and rape of African females, who refused to convert.
Conversion to Islam also came about as a result of the breakdown of historically religiously organized societies: with the weakening of many churches, for example, and the favoring of Islam and the migration of substantial Muslim Turkish populations into the areas of Anatolia and the Balkans, the "social and cultural relevance of Islam" were enhanced and a large number of peoples were converted. This worked better in some areas (Anatolia) and less in others (e.g. the Balkans, where "the spread of Islam was limited by the vitality of the Christian churches.")
Along with the religion of Islam, the Arabic language and Arab customs spread throughout the empire. A sense of unity grew among many though not all provinces, gradually forming the consciousness of a broadly Arab-Islamic population: something which was recognizably an Islamic world had emerged by the end of the 10th century. Throughout this period, as well as in the following centuries, divisions occurred between Persians and Arabs, and Sunnis and Shiites, and unrest in provinces empowered local rulers at times.
Conversion within the Empire: Umayyad Period vs. Abassid Period
There are a number of historians who see the rule of the Umayyads as responsible for setting up the "dhimmah" to increase taxes from the dhimmis to benefit the Arab Muslim community financially and to discourage conversion. Islam was initially associated with the ethnic identity of the Arabs and required formal association with an Arab tribe and the adoption of the client status of mawali. Governors lodged complaints with the caliph when he enacted laws that made conversion easier, depriving the provinces of revenues.
During the following Abbasid period an enfranchisement was experienced by the mawali and a shift was made in the political conception from that of a primarily Arab empire to one of a Muslim empire and c. 930 a law was enacted that required all bureaucrats of the empire to be Muslims. Both periods were also marked by significant migrations of Arab tribes outwards from the Arabian Peninsula into the new territories.
Conversion within the Empire: Conversion Curve
Richard Bulliet's "conversion curve" shows a relatively low rate of conversion of non-Arab subjects during the Arab centric Umayyad period of 10%, in contrast with estimates for the more politically multicultural Abbasid period which saw the Muslim population grow from approx. 40% in the mid 9th century to close to 100% by the end of the 11th century.. This theory does not explain the continuing existence of large minorities of Christians in the Abbasid Period. Other estimates suggest that Muslims were not a majority in Egypt until the mid-10th century and in the Fertile Crescent until 1100. Syria may have had a Christian majority within its modern borders until the Mongol Invasions of the 13th century.
Later, the Ottoman Empire set on to conquer territories from these rivals: Cyprus and other Greek islands (except Crete) were lost by Venice to the Ottomans, and the latter conquered territory up to the Danube basin as far as Hungary. Crete was conquered during the 17th century, but the Ottomans lost Hungary to the Holy Roman Empire, and other parts of Eastern Europe, ending with the Treaty of Carlowitz (1699).
Under the Umayyad and Abbasid Caliphs, Christianity enjoyed, with few exceptions, great freedom and respect throughout all the Muslim Empire, as can be seen from the facts and data collected by Assemani and Bar-Hebraeus, according to which many Nestorian and Jacobite patriarchs from the seventh to the eleventh centuries received diplomas, or firmans, of some sort from prophet Muhammad himself, from Umar, Ali, Marwan, Al-Mansur, Harun al-Rashid, Abu Ja'far, and others. (Shedd, op. cit., 239-241; Assemani, De Catholicis Nestorianis, 41-433 sqq.; Bar-Hebraeus, Chronicon Ecclesiasticum I, 309, 317, 319, 325; II, 465, 625; III, 307, 317, 229, 433, etc.; and Thomas of Marga, op. cit., II, 123, note.)
In 635 Damascus surrendered, its inhabitants being promised security for their lives, property, and churches, on payment of a poll tax. by 640 the conquest was virtually complete. The Arab garrisons were kept apart in camps, and life went on much as before. Conversion to Islam had scarcely begun, apart from Arab tribes already settled in Syria; except for the tribe of Ghassan, these all became Muslim. Christians and Jews were treated with toleration, and Nestorian and Jacobite Christians had better treatment than they had under Byzantium . The loyalty of his new subjects was paramount to the success of Muslim rule in the region, therefore excessive taxation or oppression was avoided.
Like their Byzantine and late Sasanian predecessors, the Marwanid caliphs nominally ruled the various religious communities but allowed the communities' own appointed or elected officials to administer most internal affairs. Yet the Marwanids also depended heavily on the help of non-Arab administrative personnel and on administrative practices (e.g., a set of government bureaus). As the conquests slowed and the isolation of the fighters (muqatilah) became less necessary, it became more and more difficult to keep Arabs garrisoned. As the tribal links that had so dominated Umayyad politics began to break down, the meaningfulness of tying non-Arab converts to Arab tribes as clients was diluted; moreover, the number of non-Muslims who wished to join the ummah was already becoming too large for this process to work effectively.
The Muslims arrived at Jerusalem around early November 636, and the Roman garrison withdrew into the fortified city. For four months the siege continued, every day there was a fierce assault. At last, when all further resistance was hopeless, the Patriarch Patriarch Sophronius (who acted throughout as the head of the Christian defenders) appeared on the walls and demanded a conference with Abu Ubaidah. He then proposed to capitulate on fair and honourable terms; the Christians were to keep their churches and sanctuaries, no one was to be forced to accept Islam. Sophronius further insisted that these terms should be ratified by the caliph in person. Caliph Umar, then at Medina, agreed to these terms and came with a single camel to the walls of Jerusalem. He signed the capitulation, then entered the city with Sophronius "and courteously discoursed with the patriarch concerning its religious antiquities" . It is said that when the hour for his prayer came he was in the Anastasis, but refused to say it there, lest in future times the Muslims should make that an excuse for breaking the treaty and confiscating the church. The Mosque of Omar (Jami 'Saidna 'Omar), opposite the doors of the Anastasis, with the tall minaret, is shown as the place to which he retired for his prayer. Under the Muslim the Christian population of Jerusalem in the first period enjoyed the usual toleration given to non-Muslim theists. The pilgrimages went on as before. From that point, the rights of the non-Muslims under Islamic territory were governed by the Pact of Umar, and Christians and Jews living in the city were granted autonomy in exchange for a required poll tax (jizya).
The description of Arculf, a Frankish bishop who went on a pilgrimage to the Holy Land in the seventh century, written down from his account by Adamnan, monk of Iona (d. 704): "De locis terrae sanctae", lib. III (P. L., LXXXVIIl, 725 sq.), gives us a not unpleasant picture of the conditions of Christians in Palestine in the first period of Muslim rule. The caliphs of Damascus (661-75O) were enlightened and tolerant princes, on quite good terms with their Christian subjects. Many Christians (e.g. St. John Damascene, d. c. 754) held important offices at their court. The Abbaside caliphs at Bagdad (753-1242), as long as they ruled Syria, were also just and tolerant to the Christians. The famous Harun Abu-Ja-'afar (Haroun al-Raschid, 786-809) sent the keys of the Holy Sepulchre to Charlemagne who built a hospice for Latin pilgrims near the shrine.
During the Fatimid rule, Romans were attacking Syria. It was inevitable that the Christians of Jerusalem should try to help their fellow-countrymen to reconquer the land that had been Roman and Christian; inevitable, too, that the Muslims should punish such attempts as high treason. In 969 the patriarch, John VII, was put to death for treasonable correspondence with the Romans; many other Christians suffered the same fate, and a number of churches were destroyed. The infamous Hakim (Al-Hakim bi-amr-Allah, the sixth Egyptian Caliph, 996-1021, who became the god of the Druze) determined to destroy the Holy Sepulchre (In 1010). It was one of the causes of the feeling that eventually brought about the First Crusade. It has been rebuild in 1048.
It used to be argued that Zoroastrianism quickly collapsed in the wake of the Islamic conquest of Persia due to its intimate ties to the Sassanid state structure. Now however, more complex processes are considered, in light of the more protracted time frame attributed to the progression of the ancient Persian religion to a minority; a progression that is more contiguous with the trends of the late antiquity period. These trends are the conversions from the state religion that had already plagued the Zoroastrian authorities that continued after the Arab conquest, coupled with the migration of Arab tribes into the region during an extended period of time that stretched well into the Abbassid reign. While there were cases such as the Sassanid army division at Hamra, that converted en masse before pivotal battles such as the Battle of al-Qādisiyyah, conversion was fastest in the urban areas where Arab forces were garrisoned slowly leading to Zoroastrianism becoming associated with rural areas. Still at the end of the Umayyad period, the Muslim community was only a minority in the region.
Considerable controversy exists both in scholarly and public opinion about the conversions to Islam. Embedded within this lies the concept of Islam as a foreign imposition and Hinduism being a natural condition of the natives who resisted, resulting the failure of the project to Islamicize the Indian subcontinent and is highly embroiled with the politics of the partition and communalism in India. These are typically represented by the following schools of thought:
Some of the Mongolian tribes became Islamized. Following the brutal Mongol invasion of Central Asia under Hulagu Khan and after the Battle of Baghdad (1258) Mongol rule extended across the breadth of almost all Muslim lands in Asia,and the caliphate was destroyed and Islam was persecuted by the Mongols and replaced by Buddhism as the official religion of the land. In 1295 however, the new Khan of the Ilkhanate, Ghazan converted to Islam and two decades later the Golden Horde followed suit. The Mongols had been religiously and culturally conquered, this absorption ushered in a new age of Mongol-Islamic synthesis that shaped the further spread of Islam in central Asia and the Indian subcontinent.
In the 1330s the Mongol ruler of the Chagatai Khanate converted to Islam, causing the eastern part of his realm called Moghulistan to rebel. However during the next three centuries these Buddhist, Shamanistic and Christian Turkic and Mongol nomads of the Kazakh Steppe and Xinjiang would also convert at the hands of competing Sufi orders from both east and west of the Pamirs. The Naqshbandi's are the most prominent of these orders, especially in Kashgaria where the western Chagatai Khan was also a disciple of the order.
Byzantine rule was ended by the Arabs, who invaded Morocco in 682 in the course of their drive to expand the power of Islam. Except for the Jews, the inhabitants of Morocco, both Christian and pagan, soon accepted the religion of their conquerors. Berber troops were used extensively by the Arabs in their conquest of Spain, which began in 711.
No previous conqueror had tried to assimilate the Berbers, but the Arabs quickly converted them and enlisted their aid in further conquests. Without their help, for example, Andalusia could never have been incorporated into the Islamicate state. At first only Berbers nearer the coast were involved, but by the 11th century Muslim affiliation had begun to spread far into the Sahara
The Marwanid Maghrib illustrates a kind of conversion more like that of the peninsular Arabs. After the defeat of initial Berber resistance movements, the Arab conquerors of the Maghrib quickly incorporated the Berber tribes en masse into the Muslim community, turning them immediately to further conquests. In 710 an Arab–Berber army set out for the Iberian Peninsula under the leadership of Tariq ibn Ziyad.
Along the coast of Africa Islam spread among the Berbers and Somalis(who converted to Islam in 7th century when the first muslims migrated to Abyssinia), who joined the Muslim community and almost immediately drove north across the Mediterranean into Europe. On the east coast of Africa, where Arab mariners had for many years journeyed to trade, Arabs founded permanent colonies on the offshore islands, especially on Zanzibar, in the 9th and 10th cent. From there Arab trade routes into the interior of Africa helped the slow acceptance of Islam. In the 20th cent. Islam has gained more converts in Africa than has Christianity, which labors under the burden of identification with European imperialism.
"Toleration, a common language and a long tradition of separate rule all helped to create a distinctive Andalusian consciousness and society. Its Islamic religious culture developed on rather different lines from those of the eastern countries, and its Jewish culture became independent of that of Iraq, the main centre of Jewish religious life." Muslim Andalusia is particularly interesting because there the pressure for large-scale conversion that was coming to plague the Umayyads in Syria, Iraq, and Iran never developed.
During the 11th century, the Umayyad caliphate in al-Andalus broke up into smaller kingdoms called Taifas, which in the end created the preconditions for the Christian reconquest. The latter re-established Christian rule more and more southwards, ending all Muslim rule in 1492 with the reconquest of the Kingdom of Granada. Virtually all Muslims and also all Jews found themselves forced to either convert to Christianity or leave the country - the result was an exodus of both Muslims and Jews to North Africa, resulting not only in a loss of business but also in a massive brain drain for the time being.