How Islam Spread Throughout the World

Historians have widely discredited the narrative that the prevalence of Islam in the world today can be explained as a result of forced conversions. Without denying that there may have been some exceptional cases of forced conversion―in blatant violation of clear Islamic directives―this article describes some of the prominent factors in the Islamization of different regions of the world in history, including daʿwah, trade, intermarriage, migration, influencers, Islam’s emphasis on justice and unity, and the universality of Islam. The examples used in this article are not exhaustive, but they help us develop an appreciation of the complex nature of the spread of Islam, a process which certainly cannot be oversimplified into a slogan such as “Islam was spread by the sword.”

In 1993, the historian Richard Eaton claimed that “Islam was history’s first truly global civilization.” While the present status of the Muslim ummah (community) as a functional “civilization” is up for discussion, the scope referenced by Eaton is more accurate today than ever: Islam today is undeniably a global dīn (way of life), professed by an estimated 1.8 billion people as of 2015. For some, the prevalence of one of the world’s youngest religions can only be explained by the “fact” that historically, Islam “spread by the sword”―that is, through systematic forced conversion. As discussed in the first article in this series, this is a very shallow assertion. However, the previous analysis does raise another important question: if Islam was not spread by the sword, what are the factors that have led to its prevalence across the world today?

The current article discusses these factors and their role in Islam’s historical trajectory in different regions of the world. This analysis is organized in the following way. The first section covers five prominent factors that explain how non-Muslims were exposed to the message of Islam: daʿwah, trade, intermarriage, migration, and influencers. The second section covers three prominent factors that primarily explain why non-Muslims embraced this message after they were exposed to it: Islam’s emphasis on justice and unity, and the universality of Islam.

It is important to note that this is not an exhaustive list―in fact, every individual convert had his or her own particular experiences that led them to embrace the faith. However, to discuss each case would be redundant, even if it were possible. It is therefore necessary to generalize the discussion on the spread of Islam for the sake of a meaningful analysis, but not in such a way as to lose sight of the reality: there have been virtually countless different means used to deliver the message of Islam, and countless different reasons for accepting it.

Daʿwah

Daʿwah, or the act of inviting others to engage with the message of Islam, follows naturally from the Muslim’s obligatory concern for humanity’s success and salvation. “Invite (udʿū) all to the Way of your Lord with wisdom and kind advice” (16:125) is a clear Qurʾānic directive to Muslims. Allāh also informs Prophet Muhammad ﷺ of his mission in the Qurʾān (33:45-6): “O Prophet! We have sent you as a witness, and a deliverer of good news, and a warner, and a caller (dāʿī) to [the Way of] Allāh by His command, and a beacon of light.” After the Prophet ﷺ, every member of the Muslim ummah shares in the responsibility of daʿwah to the extent they are able.

An early dāʿī was Muʿādh ibn Jabal, sent by the Prophet ﷺ to give daʿwah in Yemen and Hadramawt. The importance of this task is indicated in a letter sent by the Prophet to his contacts in Yemen after dispatching Muʿādh, in which he said, “I have sent you my best man.” According to the historian Ibn Ishāq, the Prophet ﷺalso instructed Muʿādh on the manner of daʿwah before he left, including the following: “Be tolerant, not harsh; spread the word, and do not alienate them.” Bukhārī and Muslim also recorded a version of this narration.

Muʿādh was constantly on the move throughout the region, not settling in one place for too long, so as to maximize the reach of his daʿwah. It is noteworthy that this same region soon became the point of departure for traveling scholars and merchants who introduced Islam to many parts of the world, such as Madagascar, parts of Southeast Asia (as discussed below), and elsewhere. As one scholar has noted, “there exists archeological evidence pointing to a Yemeni mosque—what exactly that means is open to debate—in Quangzhou from the eleventh century, and to a tombstone from Mogadishu dated 1358.”

The role of the daʿwah efforts of Sufi Muslims in the spread of Islam is widely recognized. An archeological study of the oldest surviving Islamic monuments in present-day western Kazakhstan concluded that these were “built under the influence of the Sufi strand of Islam, which retained its influence in the Kazakh steppes until the early fifteenth century,” indicating that Sufism played an important role in the initial spread of Islam in this region. This reinforces earlier suggestions of the influence of traveling Sufis such as Abū’l-Hasan al-Kalamātī and Abū’l-Hasan al-Usbānīkathī (both fl. 10th century) in the spread of Islam in Central Asia, particularly during the period of Sāmānid rule (819-999). 

Similarly, Sufism played a leading role in the Islamization of Kashmir, a disputed territory in the foothills of the Himalayas with a population that is currently upwards of 95% Muslim. It is difficult to pinpoint the beginning of the Islamization of Kashmir, but there are records of a Syrian Muslim military general arriving there, possibly as a prisoner of war, as early as 711. There are also records of Kashmir’s Hindu kings requesting Islamic scholars to be sent to their courts, ordering the Qur’an to be translated into the Kashmiri language, and employing Muslims in their court administration and army.

However, the more precisely traceable history of Islam in Kashmir dates to 1323, when the Buddhist ruler of Kashmir, Lha (also known as Rinchen), “subjected himself to the teachings of the religion of Mustafa [i.e., the Prophet ﷺ], and the right principles of the truthful path of Murtaza [i.e., ʿAlī ibn Abī Tālib], and embraced the Islamic religion with sincerity and conviction.” Lha (after conversion, Mālik Sadr al-Dīn) was an “inquisitive and alert” young man, “fond of the company of learned men,” and he had been inspired during a meeting with a traveling Sufi scholar known as Bulbul Shah (d. 1327), reportedly because he found that Islam was “simple, free from useless ceremonies, caste, and priesthood.” 

Mālik died shortly after his conversion, but not before he helped Bulbul Shah establish a khanqah (a Sufi school) and a langar khāna (community kitchen) that fed the poor of all backgrounds twice a day. Many Kashmiris converted at the hands of Bulbul Shah. One of his students, Ahmad, later became the chief Islamic scholar of Kashmir under Shah Mīr, Mālik’s former chief minister and also a Muslim, who came to power in 1339. Thus began the Shah Mīrī (or Swati) dynasty; his descendants ruled Kashmir for the next two centuries. It was during this time that another Sufi scholar, Mīr Sayyid ʿAlī al-Hamdānī (d. 1385), came to the region to teach Islam, ushering in the second wave of da‘wah to Islam in Kashmir. In addition to Kashmir, the widely-traveling Hamdānī is known for his da‘wah in parts of Syria, Iraq, Khawarzm, Central Asia, India, and possibly even Sarandīp (Sri Lanka). 

A prominent example of Sufi daʿwah is that of the Ba ʿAlawi tarīqah (order) started by Muhammad ibn ʿAlī al-Faqīh al-Muqaddam (d. 1255) of Hadramawt in Yemen; hence the Ba ʿAlawis are also referred to as Hadramīs. Due in large part to a shift in trade routes due to the Mongol conquest of Baghdad in 1258 (discussed in detail below), starting in the 14th century, members of the Ba ʿAlawi tarīqah increasingly traveled to the Malay-Indonesian Archipelago via India for trade, migration, and daʿwah. As Ulrike Freitag has noted in her study of Islam in this region, “the emergence of Sufism, and from the twelfth century onwards the Sufi orders, offered religious practices which were attractive to non-Muslims as well. Charismatic Sufis who knew how to read and write, who practiced medicine [...] drew Muslims and non-Muslims alike into their circles.” 

Other reasons for why the Sufi daʿwah of the Ba ʿAlawi was so effective in this region―given that some 250 million Muslims live in Southeast Asia today―are outlined elsewhere in this article, though more research on their impact is needed. As Syed Farid Alatas has noted, discussion of their daʿwah has been “conspicuously absent in the literature on the history of Islam in Southeast Asia.” 

Some indicators of the effectiveness of daʿwah in the spread of Islam are seen in the frantic measures taken by some authorities to try to prevent Muslims from carrying out daʿwah work. The enslaved Muslims brought by early Spanish colonizers to the “New World,” for example, often escaped and ran away, finding refuge in Native American settlements. The Spanish authorities feared both the spread of Islam in their colonies and the prospect of joint African–Native American rebellions. The depth of their anxiety was reflected in the severity of punishments; one runaway slave who was plausibly Muslim was recaptured and boiled to death in Costa Rica in 1540, and two Muslims were condemned (one to death, one to life in prison) in 1560 for “having practiced and spread Islam in Cuzco, Peru.” On five different occasions in the 16th century, Spanish authorities passed legislation in efforts to limit the influx of Muslim slaves into the colonies; they were described as an “inconvenience,” at least partially due to their daʿwah activity. 

Following in this tradition, Muslims have given daʿwah in different ways virtually everywhere they have gone, and it is therefore not far-fetched to claim that daʿwah has been the most important factor in the spread of Islam. Every example of conversion to Islam that is described in this article involves daʿwah in some form.

Trade

The Prophet Muhammad ﷺ himself was a merchant at one stage of his life, and trade has historically been instrumental in the spread of his message. The lands that came under Muslim rule after the early conquests included some of the most important trade routes (e.g., large parts of the Silk Road), commercial centers (e.g., Damascus), and ports (e.g., Aden) of the pre-modern world. The Muslims also inherited the ever-lucrative spice trade flowing across the Indian Ocean. As Muslim merchants traveled, they inevitably―and, it may be assumed, often very deliberately―exposed non-Muslims to their beliefs, values, and way of life.

The early emergence of Muslim communities on the Malabar Coast in southwestern India is a fitting example of the role of trade in the spread of Islam. The pre-Islamic Arabs and Persians frequently visited the ports of the Malabar Coast to trade with merchants coming from further east. These connections were so strong that there is a mosque, called Cheraman Jāmiʿ Masjid, that is widely believed to have been originally built by Muslim traders in 630―during the lifetime of Prophet Muhammad ﷺ.

The narrative of the origins of this mosque is unverifiable, but it does indicate the possibility of a very early Muslim presence on the Malabar Coast. The Muslim traders who settled in Malabar and intermixed with the local population came to form the Māppila Muslim community that is prevalent in the region today. By the 10th century, according to the ʿAbbāsid historian al-Masʿūdī, a settlement called Saymur (south of present-day Mumbai) was home to about 10,000 Muslims. Many of these are likely to have been indigenous converts, the “great majority” of them embracing Islam to escape their status as downtrodden, low-caste Hindus. 

Looking further east, it is arguably no coincidence that China’s oldest and largest mosque―the Great Mosque of Xi’an, thought to have been built in 742 CE―stands in the city (then known as Chang’an) that marked the easternmost point of the Silk Road. In addition to Chang’an, early Persian and Arab Muslim merchants also traveled by sea to Guangzhou, Quanzhou, and Kaifeng; the ʿAbbāsid ruler al-Mansūr (d. 775) boasted that there were no obstacles for trade between his new capital, Baghdad, and these commercial centers. An estimated 120,000 “non-Chinese,” including Muslims, Christians, Jews, and Zoroastrians, were killed in Guangzhou in 877 during a rebellion, providing us with a sense of how many Muslims (most of them merchants) traveled to and settled in Guangzhou alone. Trade took Muslims as far as “al-Shīla” (Korea), where many of them had settled by the late 800s.

In the case of Southeast Asia, there is evidence dating as far back as the 7th century that Arab traders were active in the region, especially in Sumatra (Indonesia). A shipwreck found off the coast of Java and dated to the year 960 included a stone mold to make medallions that read “al-mulk lillāhi al-wāhid al-qahhār” (“All Sovereignty is Allāh’s, the One and Only, the Dominator”). By the 10th century, communities of Muslim traders had started to settle in Southeast Asia, the most prominent of them in Champa (Vietnam), from which the present-day Cham Muslims of Cambodia and Vietnam originate. By the 11th century, they were active in present-day Brunei and the Philippines.

A key turning point in the Islamization of Southeast Asia was the Mongol conquest of Baghdad in 1258. Given the damage done to infrastructure and the breakdown of authority in Iraq, the Persian Gulf and the Tigris-Euphrates river system could no longer serve as the primary trade route for the spice trade from the Indian Ocean to the Mediterranean, including rising European markets. The Red Sea route rose to prominence, including the ports of Alexandria, Cairo, Jeddah, Aden (from where Hadramī dāʿīs often embarked, headed east), Cambay (Gujarat and Mumbai), Calicut, and Pisai (Malacca and Aceh). Freitag has noted that “the presence of high status and economically successful [Muslim] merchants seems in itself to have provided an example which seemed well worth emulating. Conversion to the faith of the economic elite held advantages such as the promise of becoming part of an international commercial network.” 

By the 14th century, the spread of Islam across Southeast Asia was well underway, peaking with the prosperity of the Sultanate of Malacca (1403-1511); notably, the rulers of Cambay and Aceh were also Muslim by the early 15th century. According to the Portuguese apothecary Tomé Pires, who visited Malacca in 1507, it was the most important city in the world, and whoever controlled it “shall have his hands on the throat of Venice”―a reference to Europe’s reliance on the spice trade that flowed through the city. 

The spread of Islam in Eastern Europe offers another example of the central role of trade in this process. In the late 1930s, an Arabic silver coin dating from the time of the Umayyad ruler Marwān II (r. 744-50) was found in the village of Potoci in Herzegovina. In nearby Hungary, Muslims had served as minters and money-changers for the court, had been heavily involved in the customs system, and had controlled the production and sale of salt, all before the Golden Bull of 1222 declared that no Muslim or Jew could serve in the administration. Much earlier, King Ladislas I (r. 1077-95) had referred to certain merchants in Hungary, called “Ishmaelites” who had nominally converted to Christianity but continued to profess and practice Islam. And in 2013, excavations at a cemetery in Orosháza revealed that the bodies had been buried with their heads facing south (i.e., in the direction of the Kaʿbah, as per Islamic practice). The village also showed an unusual “lack of pig bones” and the presence of measuring devices, strongly suggesting that its inhabitants were Muslim merchants.

Another case of trade serving as the avenue for the spread of Islam is that of East, Central, and West Africa. Due to their proximity, Arabia and East Africa had a long pre-Islamic history of close political and trade relations. Soon after the advent of Islam, merchants took the lead in introducing the faith to this region. The East Africans developed and maintained close ties with Muslim outposts in the Indian Ocean, especially the ports of Yemen, the Persian Gulf, and India; this brought with it so much cultural exchange that Ibn Battūtah, traveling in the 1300s, noticed that the same food he had enjoyed in Mogadishu (Somalia), Mombasa (Kenya) and Kilwa (Tanzania) was offered to him in Sarandīp (Sri Lanka). The merchants’ “delivery” of Islam was bolstered by a steady stream of refugees coming from Arabia in the 7th-10th centuries, many of them fleeing civil wars or natural disasters. One of them, ʿAlī ibn al-Hasan Shirāzī, later established the Kilwa Sultanate, which at its peak covered the entire Swahili Coast. Despite all of this trade and settlement, it was not until the 13th century that the Islamization of East Africa started to accelerate. 

The baqt in Sudan played a key role in the spread of Islam in East-Central Africa. In 652, having completed the conquest of Egypt, Muslim forces moved south and met Nubian forces at Dongola (Sudan). Rather than press for a fight, the two sides agreed to a baqt, or peace agreement, which was remarkably honored for six centuries. The baqt enabled Muslim scholars and traders to travel freely in the region, thereby introducing Islam to the Nubians. During the early 9th century, large deposits of gold and emeralds were discovered in the desert south of Aswan. This prompted Egypt’s Arab Bedouin tribes, many of whom had firmly embraced Islam by this point, to migrate into this region, and, over time, to penetrate deep into present-day Sudan and settle down. It is clear that the spread of Islam in this region took centuries, and Islam could be said to have supplanted Christianity in the area of Nubia only by the 14th century at the earliest.

In the Central-West African region, too, Islam was introduced by Muslim merchants from North Africa. It is no coincidence that some of the first towns to develop a significant Muslim population in this region were Awdaghust (Mauritania) and Tadmekka (Mali), two of the southern termini of the famous Trans-Saharan trade route. The geographer Ibn Hawqal (d. c. 988) recorded that Kumbi Saleh, the capital of the Ghana Empire, had a neighborhood of Muslim merchants. Around the years 1009 and 1040, respectively, the kings of Takrur (Senegal) and Gao (Mali) had embraced Islam. By 1085, Islam was spreading quickly in Kanem (Chad-Nigeria). These developments, virtually all initiated by Muslim merchants, paved the way for powerful Afro-Muslim empires such as that of Mansa Musa, which in turn facilitated the further spread of Islam in the region, as described above. And, as was the case in many places, Islamization here was a very long process and was still observably underway when the German explorer Heinrich Barth traveled through the region in the 1850s.

Migration

Migration, both forced (e.g., as slaves or refugees) and voluntary (e.g., economic migration), has played an important role in the spread of Islam, especially since the 15th century. However, there are earlier examples; in fact, the earliest presence of Muslims outside of Arabia was that of a group of Muslims who sought refuge in Abyssinia during the lifetime of Prophet Muhammad ﷺ and at his instruction. 

It should be noted that though Muslims who have been forced to migrate have given daʿwah—an example of this was given in the section on daʿwah above, and another example is that effective daʿwah of Jaʿfar ibn Abī Tālib to the Abyssinian ruler, the Negus—the argument here is that their mere presence in the regions to which they were relocated can be seen as a form of the spread of Islam. In other words, as Sylviane Diouf and others have argued, wherever these Muslims went they commonly brought with them their embodied knowledge of Islam.

Forced migration brought the first Muslims to the “New World” by way of the Transatlantic Slave Trade, laying the foundations for an early Muslim presence in the Americas. It has proven difficult to reliably estimate how many slaves of African origin were Muslim, but they must have numbered at least in the hundreds of thousands. The United States makes for a useful case study, and it may have held a higher proportion of Muslim slaves than any other region in the Americas. 24% of the African slaves brought to the Thirteen Colonies or, later, the United States were from Senegambia, which makes it likely that they were Muslims. The city of St. Augustine, Florida is the oldest continuously-occupied European city in the mainland United States, and was originally built largely by African Muslim slave laborers. 

Gradually, the descendants of these forced migrants became distanced from Islam, but they held on to enough awareness of their heritage so as to establish pseudo-Islamic communities in the early 20th century, such as the Moorish Science Temple of America (MSTA) and the Nation of Islam (NOI), and to eventually return to mainstream Islam en masse starting in the late 1970s. Today, Muslims of African descent make up around 25% of the U.S. Muslim population. 

A less known case of forced migration of Muslims occurred by way of the Indian Ocean slave trade organized by the Dutch East India Company (DEIC). The first known Muslims in present-day South Africa, the Amboyan Mardyckers from Southeast Asia, had arrived in 1658 not as slaves but as political prisoners or mercenaries for the DEIC. However, the DEIC soon began to transport slaves to Cape Town, obtaining them from the Muslim-majority regions of East Africa, South Asia (especially the Arakan-Bengal coast), and the Southeast Asian islands by raiding the coasts. By 1731, 42% of the population of Cape Town were slaves; it is noteworthy that a significant portion of these may have been Rohingya Muslims.

Educated Muslims from Southeast Asia―especially Shaykh Yūsuf al-Maqassarī (d. 1699) and Tuan Guru (d. 1807), both of them exiled political prisoners―established the roots of Islam in South Africa. Shaykh Yūsuf’s farm at Zandvliet became a sanctuary for fugitive slaves from Cape Town. Tuan Guru established Cape Town’s first madrasah (Islamic seminary) in 1793, and the city’s first mosque was opened in 1798. By 1850, about 40% of Cape Town’s population was Muslim, and by 1891 their number had risen to over 11,000, in part due to the arrival of indentured laborers from South Asia starting in the 1860s. 

Examples of voluntary (or economic) migration are more numerous, especially because this has been the driving force behind the spread of Islam to virtually every country in the world―even those as remote as Fiji―since the 19th century. One example is that of the famous Afghan (and Baluchi) cameleers who “helped to pioneer Australia,” particular the vast Outback, where they did everything from exploring and conducting rescue missions to laying railway and telegraph lines. In the process, they married European or Aborigine women and established their own settlements, which were generally built around a small, makeshift mosque. Another example is that of Canada, where Lebanese Muslim immigrants began to arrive in the late 19th century, often hoping to take part in the Klondike Gold Rush or the lucrative fur trade; some of them, such as Ali Abouchadi, became very successful entrepreneurs and laid the foundations for Canada’s present-day Muslim community. 

Intermarriage

Intermarriage between Muslims and non-Muslims has been historically important for the spread of Islam in many contexts. This is an area of research that only recently has begun to receive attention, as most converts to Islam via this process were women and, as Maya Shatzmiller noted in 1996, “not only was woman’s voice on the subject [of conversions] absent, but the sources devised a historiographical debate from which the feminine perspective was omitted all together.” More than two decades after this observation, there is a significant body of research that has explored the nexus of intermarriage and conversion in Islamic history, but much more work needs to be done in this field.

Conversion through intermarriage was important to establishing the early Muslim community Spain. In around 785, Pope Hadrian in Rome wrote a letter expressing his concern that some Catholics in Hispania seemed only too willing to marry into Arab Muslim families, and Christian-Muslim unions were condemned at a council in Cordoba in 836. One prominent case was that of Sarah, daughter of Alamund of the Visigothic royal family. She was married twice to prominent Muslims, and in later centuries her descendants formed some of the leading Muslim families of Seville, including the Banū Hajjāj and Banū Maslamah. One of her descendants was the famous scholar of history, fiqh (jurisprudence) and hadīth (Prophetic narrations), Ibn al-Quṭiya (d. 971), who prominently mentioned the role of his great-grandmother in his discussion on the early history of Islam in al-Andalus. A similar case is that of the daughter of the Visigothic nobleman Theodomir (d. 743), who married one ʿAbd al-Jabbār ibn Khaṭṭāb. The descendants of this couple came to be known as the Banū Khaṭṭāb and formed an influential family of Islamic scholars that lasted until the end of Islamic rule in Murcia in the 13th century. 

The early modern Ottoman Empire also offers many examples of intermarriage involving conversion. A case in point is that of Beatrice Michiel of Venice who, in 1591, “opted for conversion without coercion or compulsion” and changed her name to Fatima Hatun. Having been raised a Christian and married twice, she escaped her difficult second marriage by fleeing to Constantinople, where she converted to Islam and married one ʿAlī Agha. Her son from her first marriage, Giacomo, followed his mother into Islam nearly a decade later. A similar case was that of the wife, unnamed in the sources, of Ferenc Csiszar, a man from 16th-century Várad (present-day Oradea, Romania). She reportedly went to Buda (Budapest) to marry a “Turk,” which in all likelihood involved a conversion to Islam despite this not being a condition for the marriage. This trend was noted by the Jesuits involved in missionary work in Ottoman-ruled Hungary. It was also common enough for King Matthias Hunyadi (r. 1458-90) to feel compelled to write to the Pope requesting that the Christian men—and in some cases, women—whose spouse had left to convert to Islam should be allowed to remarry rather than hope for their spouse’s eventual return or worse yet, go searching for their spouse in Ottoman territory and potentially convert to Islam themselves in the process.

In British-ruled India, several dalit women (i.e., those from the downtrodden Hindu caste of “untouchables”) converted to Islam as part of intermarriage with Muslims. There are at least nine reported cases between 1924 and 1946, though four of these occurred between March and May in 1926 alone. Considering that these were only the cases that were registered by the colonial police force in the province of Uttar Pradesh (UP) because they sparked significant unrest, the actual rate of conversion may have been much higher. It has been noted that although there were active daʿwah efforts among the dalits of UP, “in many cases of individual conversion, particularly by lower castes, the reason [for intermarriage] was neither proselytism nor doctrinal conviction, but romance,” though romantic motivations were “possibly aided by greater mobility.”

Intermarriage has continued to play an important role in conversion to Islam in more recent times. One case is that of immigrant Muslims marrying Latina women in the United States in the mid-20th century. A 1947 study of Palestinian immigrants in Chicago revealed that one man had married a Mexican-American woman and had children with her. Similarly, and from around the same time, there are records of Yemeni Muslim men in southern California marrying Mexican-Americans and South Asian Muslims in Harlem marrying Puerto Rican-Americans. By the early 1990s, there were an estimated 100 Latino converts to Islam in southern California alone, mostly women who had married Muslims since the mid-1970s. A noticeable trend in their conversions was that “the conversion of one woman would lead to a string of conversions within her family.” After having converted, these Latina Muslims led the effort to perform daʿwah in Latino communities in the U.S.

Another recent case is that of Chinese and Filipina women in Hong Kong converting to Islam through their marriages to South Asian Muslims. Muslims from British-ruled India first arrived in Hong Kong in significant numbers in the early 20th century as employees of the British administration. During the Japanese occupation of Hong Kong during the Second World War, many disadvantaged Chinese women married these Muslims. Beginning in the early 1990s, Filipina domestic workers in Hong Kong, mostly devout Catholics aged 21-35, increasingly began to convert to Islam and to marry Pakistani Muslims. In the Wan Chai district alone, there were 100 Filipino converts between 1993 and 1996, making up for about 70% of all converts to Islam, and this trend continued strongly into the early years of the 21st century.

Influencers

The conversion of social, political, and/or personal influencers to Islam has historically played an important role in drawing their followers, admirers, subjects, and/or acquaintances closer to the message of Islam.

In the life of the Prophet ﷺ, a prominent example of an influencer was Saʾd ibn Muʿādh. Saʾd was a chieftain of one of the clans of the Banu Aws tribe of Yathrib. The Prophet had sent Musʿab ibn ʿUmayr to teach the converts in the city and to invite others to Islam, but Saʾd strongly disapproved of this and confronted Musʿab. After a conversation, Saʾd embraced Islam, and then convened his clan and asked them how they felt about him. They replied that he was their chief, excellent in judgment, and committed to their best interests. He then informed them that he had embraced Islam, and by nightfall his entire clan had followed him.

The Prophet ﷺ also sent letters to rulers in the vicinity of Arabia, implicitly acknowledging their role as social influencers and inviting them—and, through them, their followers—to Islam. These included the rulers of Abyssinia, Byzantium, and Persia, and the governors of Ghassān (an Arab Christian client state of Byzantium), Yamāmah (an Arab kingdom in present-day central Saudi Arabia), and Alexandria.

Part of the wisdom behind the Prophet’s decision to send these letters is revealed in the fact that in many parts of the world, the conversion of an influential political leader to Islam was an important milestone in the spread of Islam in that region.  The case of the Umayyad leader ʿAbd al-Malik ibn Marwān (r. 685-705) is illustrative, especially because it implicitly reveals that this process (i.e., conversion by influence) played a role even in the Islamization, even of regions that had been conquered by Muslim forces. (Shām was the first region outside of Arabia to fully come under Muslim rule). However, as Thomas Carlson has argued, the Islamization of Syria was “a multi-faceted social and cultural process” that could not be considered complete even in 1516, when the Ottomans conquered the region―nearly a thousand years after it fell under Muslim rule.

Many factors played a role in the Islamization of Shām. One of them was Shām’s centrality to the early Muslim empire, as the Umayyad dynasty (r. 661-750) chose Damascus as its capital. The Umayyads sought religious legitimacy as a means to justifying their rule, and Syria was the first region in which efforts toward that end took shape. ʿAbd al-Malik publicized Islam in Shām as a matter of policy: he made Arabic the official language of the empire’s administration, minted distinctly Islamic coins for the first time, had milestones featuring the basmalah set up to help travelers find directions and had the iconic Dome of the Rock constructed in Jerusalem. 

By institutionalizing Islam in Shām, ʿAbd al-Malik and other influencers in the region after him―including leaders such as the famous Salāh ad-Dīn (Saladin, d. 1193) and prominent Islamic scholars such as Ibn ʿAsākir, al-Nawawī, Ibn Taymiyyah, Ibn al-Qayyim, Ibn Kathīr, and al-Dhahabī (all fl. c. 13th century)―inevitably enabled non-Muslims to engage closely with Islamic beliefs, practices, and worldviews. From there, many non-Muslims chose to embrace the faith, some rejected it, and others may have even borrowed from it.

A social influencer involved in the spread of Islam in parts of Southeast Asia was the famous Chinese Muslim admiral Cheng Ho (d. 1433). Between 1405 and 1433, Ho led seven maritime expeditions for the Ming dynasty, which took him to the major ports of the Indian Ocean and as far away as Mombasa (Kenya). Curiously, many of Ho’s crew were Hui Muslims like himself, and some performed hajj during the voyages. Ho, his Muslim shipmates and the Chinese Muslim envoys who followed them to Java and other parts of Southeast Asia all helped Islam spread in this region, primarily by establishing mosques. Their pioneering efforts can be appreciated through the fact that, today, there are over 105 million Javanese Muslims, making them the fourth-largest ethnic group among Muslims (behind only Arabs, Bengalis, and Punjabis). To this day, many mosques in the region are named after the mariner, such as the Cheng Ho Mosque in Palembang, Indonesia.

A more recent example of a social influencer’s role in the spread of Islam is that of Warith Deen Muhammad, the Supreme Minister (1975-6) of the pseudo-Islamic, US-based movement known as Nation of Islam (NOI). Having embraced Sunni Islam privately, he gradually reformed the NOI to conform to the orthodox Islamic tradition and called on his followers to do the same. In what may be considered the largest mass conversion to Islam in US history, an estimated 70,000 NOI members followed W. D. Muhammad into the fold of orthodox Islam.

It is important to note that influencers were not always in privileged positions within society; “grassroots Islamization” led by personal influencers also occurred. This was the case, for example, in the Lindi and Mtwara regions of southeastern Tanzania in the early 20th century. In the late 1800s, most people in the region were not Muslim, but today Muslims form a large majority of the population. Many conversions took place between 1910 and 1950 through a process in which ordinary villagers served as “crucial mediators.” Muslim traders and Sufi scholars had long been present on the Tanzanian stretch of the Swahili Coast, but they had not been able to deliver the message of Islam in the rural areas that were further inland. At the same time as the peak of an anti-colonial struggle (culminating in the Maji Maji war of 1905-7), “ordinary villagers who had spent some time on the coast began to work as Qur’an teachers, while local networks of lineage elders endorsed the construction of mosques.” German officials described these men as schamba-waalimu (“field-teachers”). They were “otherwise undistinguished villagers, respected for their learning and commitment, but neither particularly wealthy nor of high ritual or social status,” but they are remembered for taking the initiative to “fetch” Islam from the coast and spread it across the region. 

Another case of conversion via influencers who were not in particularly privileged positions in society occurred in the early centuries of Islamic history in the form of the mawālī system of patronage. The Arabic word mawla may be used to refer to a “client” in a patron-client relationship. During the early period of Muslim rule in what is today known as the Middle East, non-Muslims would commonly become “clients,” or mawālī, of the emerging Arab Muslim elite as a way to protect and pursue their own interests. As Patricia Crone has noted, this did not necessarily require the client’s conversion to Islam. However, the opportunity to engage with their Muslim patrons is likely to have influenced many clients to convert. Soon, many of the mawālī had mawālī of their own, thus creating a “snowball effect” of conversions to Islam through personal networks of influence, especially in the first four centuries of Islamic history. 

Lastly, on the topic of the spread of Islam via influencers, it is important to briefly revisit the pioneering thesis of Richard Bulliet in this field of research. Through a quantitative analysis of the names listed in biographical dictionaries from the early centuries of Islamic history, Bulliet showed that Islam spread very slowly as evidenced by the slow rate of the change, for example, from names that were identifiably Christian to those that were clearly Muslim. Looking primarily at the Middle East, North Africa, and Spain, Bulliet also showed that the regional “conversion curves” of this period are ‘S’-shaped, accelerating as more and more of the population converted before leveling off, thus implying that people primarily chose to convert due to their personal interactions with Muslims.

Bulliet helpfully compared the spread of Islam to the model of diffusion for a new technology or technique, a process which generally also follows an ‘S’ curve: “a few innovators would first adopt the new technique, then it would catch on with a bandwagon effect causing the steep rise in the middle of the curve, and finally there would be a steadily diminishing number of new adopters as the potential market for the new technique became saturated.” Thus, Bulliet posited that the more Muslims a non-Muslim was surrounded by and personally interacting with, the more likely they were to convert to Islam, until most non-Muslims in the region had converted.

The preceding discussion focused on how the message of Islam spread. The question of why it was accepted by individuals is more difficult to explore, simply because we are unable to determine their exact motivations. Some converts, such as Malcolm X, wrote about their journey to Islam, thus giving us a glimpse into the reasons behind their decision. However, for the overwhelming majority of cases in Islamic history, we can only speculate broadly on three of the motivations that were arguably most prominent. These motivations have already been discussed in relation to the examples offered above, but are elaborated on in this section.  

The Islamic emphasis on justice

The historian Bahjat ʿAbd al-Latif has pointed out that, “[f]rom its very inception, the message of Islam showed great concern for the poor and the disadvantaged who often comprise the majority of the population, and it aimed to liberate them and raise their standing. This was perhaps one of the strongest incentives for accepting the call to Islam…” Richard Eaton has described this as the “religion of social liberation” thesis. 

This thesis is rooted in the Islamic emphasis on the pursuit of justice, in contrast to other faith traditions which allowed for (if not encouraged) passivity and promised only otherworldly salvation. Discussing the origins of Islam and the very reason for Prophet Muhammad’s personal retreats to the Cave of Ḥirāʾ leading up to the first revelation, Ahmed Afzaal has argued that “[s]ooner or later, the crisis of meaning caused by a sensitive person's encounter with the brutal fact of injustice has to be addressed in the realm of social and material reality. While one’s ideal interest lies in developing an appropriate theodicy and a hope for salvation in the hereafter, the problem of injustice can only be adequately addressed by pursuing the fulfillment of the material interest of the weak, poor, and the marginalized.” Thus it has been widely noted that many of the earliest ṣaḥābah (companions) of the Prophet ﷺ were those who were disadvantaged in Makkan society. 

It should be noted that the cases in this category, which may readily appear to be mere “conversions of convenience,” were not necessarily devoid of conviction on part of the converts. Many disadvantaged converts, such as the companions Yāsir al-ʿAnsī and Sumayyah bint Khayyat, did not convert to Islam merely because it promised to change their material reality; if that had been the case, they likely would have relapsed under the severe torture which led to their martyrdom. Rather, it is plausible to assume that they had conviction in the truth of the Islamic worldview, the appeal of which included—but was not limited to—its emphasis on social and economic justice. Of course, this is not a denial that some conversions probably were nominal, but a reminder that convenience should not simply be presumed to have been the primary motivation.

One common example of the appeal of Islam’s “social liberation” is the spread of Islam in South Asia. Hinduism’s caste system, one of the most enduring forms of social stratification in history, relegates the lower castes such as shudras (laborers) or dalits (“untouchables”) to a severely disadvantaged position, with little to no hope of upward social mobility. Thus, early Muslims in South Asia “endeavoured to carry Islam to numerous Indian castes that were despised, rejected and discriminated against. These castes accepted Islam once they became aware that it was based upon justice, equality and solidarity among human beings.” British officials observed this process underway as late as the early 1900s, and Indian historians such as Niharranjan Ray have also attested to it.

In the context of the early modern Ottoman Empire, many Christian women chose to convert to Islam because it offered them a more favorable situation. Lady Elizabeth Craven (d. 1828) of England remarked that “the Turks in their conduct towards our sex are an example to all other nations.” Muslim women in the Ottoman Empire—who were considered legal subjects at puberty—had access to many legal privileges, including the right to own and control property without male interference and the right to register their complaints in court. Non-Muslim Ottoman women could also access these Islamic courts for judgment and often did, preferring them over their own Christian or Jewish community courts. They were particularly interested in the relative freedom that Muslim women enjoyed to obtain a divorce to escape an unfulfilling marriage. Many of them went a step further and converted to Islam.

Another example is found in the context of the Second World War. In the months following the Nazi invasion of Yugoslavia in 1941, many Jews tried to escape persecution by converting to Islam. Between April and October, at least 20% of Sarajevo’s Jews embraced Islam or Catholicism. The Ustaša regime (the Nazi’s local Croatian fascist ally) was so alarmed by this that they quickly banned conversions. Nevertheless, Fehim Spaho, the Grand Mufti of Yugoslavia, urged Ustaša officials to protect the Jewish converts to Islam and instructed the ʿulamā (scholars) to offer them shelter, and many were saved from the Holocaust in this way.

Even today, this trend can be seen in the rates of conversion to Islam in prisons, particularly in the United States, which has the highest incarceration rate of any country in the world. Up to 40,000 prisoners convert to Islam in the US annually, making up about 80% of all religious conversions in the prison system. Prisoners convert for a variety of reasons, including protection (especially from the prisons’ gang and/or drug cultures), as a form of repentance and spiritual renewal, or because of the emphasis on social justice that they see as central to the Islamic tradition. This last aspect is not an overstatement; Muslims have been at the forefront of the movement for all prisoners’ rights in the U.S. since the 1960s, and even today they are “arguably the most proactive litigants” in the prison system.

The Islamic emphasis on unity

The Islamic emphasis on unity has kept Muslims connected to the religious, demographic, and sociocultural “heartland” of the ummah irrespective of their “distance”―both physical and metaphorical―from it. Practicing the obligatory pillars of Islam helped keep individual Muslims and the small, emergent Muslim communities in far-off regions united: salah (daily prayer, preferably in congregation) helped the Muslims unify locally, and hajj (pilgrimage to Makkah at least once in one’s lifetime, if physically and financially capable) helped them identify as integral members of a global ummah.

It is no surprise, for example, that after becoming the first known Japanese convert to Islam on November 1, 1909, Omar Yamaoka was disembarking in Jeddah by December 10, on his way to perform the hajj. Immediately afterward, Yamaoka’s next initiative was to have a mosque built in Japan, a physical unifying space for Japanese Muslims; the Tokyo Mosque opened in 1938. By then many other Japanese had embraced Islam and there was a trend of trying to perform the hajj soon after conversion; eight Japanese Muslims attempted to perform the hajj between 1934 and 1938, five of whom sailed for Makkah at least twice. 

Two descriptions of the sense of unity and affirmation that converts find as they perform the hajj were written in the past century by Muhammad Asad and Malcolm X.

Asad, best known for his English translation and commentary of the Qurʾān, embraced Islam in 1926 and performed the hajj soon afterward. Describing the Black Stone in the Kaʿbah, he said, “The Prophet was well aware that all the later generations of the faithful would always follow his example: and when he kissed the stone he knew that on it the lips of future pilgrims would forever meet the memory of his lips in the symbolic embrace he thus offered, beyond time and beyond death, to his entire community.” And heading to Mount ʿArafāt, he felt as if “the wind shouts a wild paean of joy into my ears: ‘Never again, never again, never again will you be a stranger!’” 

Malcolm X converted to orthodox Islam due to his experience of the hajj in 1964. He himself commented on the effect: “Islam’s conversions around the world could double and triple if the colorfulness and the true spiritualness of the Hajj pilgrimage were properly advertised and communicated to the outside world.” The hajj can thus be said to have cemented the conversions of Yamaoka, Asad, Malcolm X, and countless others.

The hajj also served as a sort of international forum and marketplace. In pre-modern times, the journey for hajj often took months, if not years, and many Muslims deliberately prolonged the journey by stopping in major cities and centers of trade and studying with scholars along the way, and by staying for extended periods of time in Makkah and Madinah to exchange news, knowledge, and ideas, and to trade in goods and services. This exchange not only provided a sustained integration into the ummah for recent converts but also opened up windows of opportunity that could lead to even more conversions.

A case in point is the famous hajj of Mansa Musa of Mali in 1324-5. He is said to have led a large caravan and carried so much gold, which he distributed in charity and gifts along the way, that it caused hyperinflation and derailed the economies of Cairo, Madinah, and Makkah for years. He became so famous for freely distributing his wealth that he inspired curiosity about his distant kingdom and thus initiated a steady stream of Muslim traders, travelers, and scholars to Mali. On his way back, he brought back many Islamic texts as well as several scholars, including the Andalusī poet and writer Abū Ishāq Ibrahīm al-Sāhilī, who settled in Timbuktu and was tasked with leading the construction of the city’s famous Djinguereber Mosque. He thus played an influential role in Timbuktu’s emergence as the preeminent Islamic city in West Africa, from where Islam gradually spread to the rest of the region.

Of course, this sense of unity extended beyond the experience of hajj as well. For example, in 1894 the Ottoman sultan chose to send a British convert to Islam, Abdullah Quilliam of Liverpool (also known for starting Britain’s first mosque), as his representative to the opening ceremony of the Shitta-Bey Mosque, the first major mosque in Lagos in present-day Nigeria. He was warmly received by Muslims across West Africa, and at least one person from the region, John Thomas Brimah, later embraced Islam after reading Quilliam’s The Faith of Islam. In the words of the Sierra Leone Weekly News, “The existence of Islam in Liverpool […] seems to have inspired West African Mohammedans [sic] with new life.”

The universality of Islam

Dr. Umar Abd-Allah said it most eloquently: “In history, Islam showed itself to be culturally friendly and, in that regard, has been likened to a crystal clear river. Its waters (Islam) are pure, sweet, and life-giving but―having no color of their own―reflect the bedrock (indigenous culture) over which they flow. In China, Islam looked Chinese; in Mali, it looked African. Sustained cultural relevance to distinct peoples, diverse places, and different times underlay Islam’s long success as a global civilization.” This reflects an established principle of fiqh (Islamic jurisprudence), articulated by Ahmad ibn Hanbal, Ibn Taymiyyah, and others, that all customs (ʿurf) are permissible by default except what is proven to be forbidden.

Richard Eaton has observed about Islamization in Bengal, particularly, that “what made Islam in Bengal not only historically successful but a continuing vital social reality has been its capacity to adapt to the land and the culture of its people, even while transforming both.” The same can be said about many of the regions to which Islam spread.

The spread of Islam has been a historic success in large part due to the fact that it generally occurred in ways that were not overtly disruptive of local cultures and lifestyles. This is a very important point in today’s sociopolitical climate, as much Islamophobic and anti-refugee rhetoric, particularly in Europe, is based on the ostensible threat of Islam to Europe’s Judeo-Christian heritage and culture. 

Historically, however, early Muslim communities generally adhered to a distinctive subculture, adopting everything they deemed acceptable in the dominant (or hegemonic) culture and refraining from what they felt clearly conflicted with their faith. The Muslims certainly exposed the non-Muslims around them to Islamic traditions and values in culturally sensitive ways but did not impose these upon anyone (though there were rare exceptions to this, as discussed previously).

An example of this is the role of literature, an important component of culture, in the spread of Islam in Southeast Asia―in particular, the corpus of the Book of One Thousand Questions. This is purported to be a collection of 1,000 questions thatʿAbd Allāh ibn Salām, a Jewish rabbi in Madinah, had put to Prophet Muhammad ﷺ before he decided to embrace Islam. Originally compiled in Arabic, it was translated into Malay and Javanese. The Javanese translations, in particular, were adapted to be relatable to Southeast Asians, both Muslims and non-Muslims, and were used to demonstrate the discursive and intellectual power of Islam and, in turn, to provide non-Muslims with a culturally-grounded text that addressed their questions about the dīn.

Another illustrative case is that of the different “bodies of practice” of Islam found on the Indian Ocean island of Mayotte, which has a population of only about 260,000 people, 97% of them identifying as Muslims. Scholars have noted that the people of Mayotte “have long considered themselves Muslim, and their allegiance to Islam is salient in ritual and cosmology.” However, though the fundis (teachers) commonly defer to the authority of the Qurʾān and Sunnah (the Prophetic example), the relative isolation of the island has allowed for peculiar local traditions to develop which interpret the scriptural texts in different ways. These range from a “religious dance” known as daira to a strict prohibition on the fundis from indulging in politics. 

Perhaps the most remarkable example of the universality of Islam is its ability to absorb even the Mongols after they caused unprecedented destruction in large parts of the Muslim domain. As Ishayahu Landa has noted, “[t]his issue is of special importance, as it provides a relatively rare case in Islamic history in which the rulers adopted their subjects’ religion and not vice versa.” Of the four khanates which were carved out of Genghis Khan’s vast empire, the Mongol leadership of three of them embraced Islam within a century of his death. The details of this process make for too deep a discussion to be dealt with here, but what is important to note is that the Mongol converts were able to fully enter the fold of the Muslim community while holding on to many of their cultural beliefs and practices. A case in point is El-Qutlugh Khatun, a Mongol princess who performed the hajj in 1323, soon after conversion. She was described by Ibn Hajar al-Asqalānī as “a good Muslim who often gave good advice to the Muslims” and it was noted that she gave large amounts of sadaqah (charity) while on her journey, including 30,000 dinars in Makkah and Madinah alone. At the same time, she was “sharp-minded and courageous/skilled in horsemanship,” rode a horse (rather than a camel, as was the norm), and personally led traditional Mongol ring hunts in the Arabian desert to feed the pilgrims she was traveling with.

As mentioned in the introduction to this article, the examples presented above are not exhaustive, nor has their relation to the spread of Islam been discussed as thoroughly as it could have been. However, they collectively serve the purpose of this article: to illustrate that Islam could—and historically did—spread by means other than “the sword” (i.e., forced conversion). The examples demonstrate the role of daʿwah, trade, intermarriage, migration, influencers in the communication of the message of Islam, the role of Islam’s characteristic emphasis on justice and unity, and the universality of Islam in the widespread acceptance of this message.

It is hoped that the many historical “moments” which make up the larger “story” of the spread of Islam will inspire readers to explore particular moments in more detail through their own research. This is essential for developing our appreciation of the complexity of the spread of Islam, which is one of the most transformative processes in human history—comparable in scale and intricacy to Christianization or secularization—and which certainly cannot be oversimplified in a slogan such as “Islam was spread by the sword.” It is also hoped that the discussion in this article can inspire and inform daʿwah efforts in the present.

Lady Evelyn Cobbold (d. 1963), a Scottish noblewoman who declared “I am a Moslem” during a private audience with the Pope, recorded the following in her diary: “The more I read and the more I studied, the more convinced I became that Islam was the most practical religion, and the one most calculated to solve the world's many perplexing problems, and to bring humanity peace and happiness.” The discussion in this article has focused primarily on some of the more prominent structural factors that have contributed to the spread of Islam, such as trade and migration. However, it is important to note that in recent years there has been a “cultural turn” in the historiography of conversion to Islam. Memoirs, diaries and other first-hand accounts of converts, in which they describe their journeys to Islam, are increasingly becoming available. These, along with a growing body of psychological research on why many people convert to Islam today, offer two important areas of further research on the subject of conversion to Islam in history.

I am grateful to Justin Parrott, Dr. Samuel Ross, and Dr. Nameera Akhtar for their insightful feedback and suggestions.