How did Islam spread throughout the world?
According to the most authoritative historical narratives, the process was mixed. It was similar to the way that Christianity spread in different parts of the world, with some notable differences. Islam spread throughout Arabia as a persecuted minority preached its message, and entered the Horn of Africa during this period as Muslim refugees fled the persecution. Eventually, the Muslims in Arabia began to defend themselves. From that time, preaching, trade, intermarriage, and military expansion were the main ways that Islam spread. Instances of Muslim military expansion are often not well understood. For example, it is not common knowledge that the intervention of Muslims was sought by oppressed groups in both Spain and Persia during the 7th century. Meanwhile, North Africa and Egypt were part of the Byzantine Empire until the Byzantines conducted aggressive military maneuvers near the Arabian border. When the Muslims responded in kind, war ensued, and the Byzantine Empire lost much of its territory to the Muslims.
When the new Muslims conquered Egypt, Persia, North Africa and India they became the rulers in those areas. However, in these same places, it often took centuries for populations to convert to Islam, mainly through interaction, intermarriage, and missionary efforts that emphasized spirituality (Sufism). Some rulers in the early years of Islamic rule (the Umayyads) actually discouraged conversion, most likely because adult men who converted would no longer pay jizya and would be eligible to join the military. Jizya was a tax paid to the government by non-Muslim men in lieu of their military service (however they were then not required to pay Zakat, which was required of Muslims to aid the poor). Moreover, significant groups living under Muslim rule, such as Christians in Lebanon and Hindus in India, never converted and continued to practice their religions until the present. In other areas, Islam spread mainly through trade and Sufi missionary activity.
However, in a few instances Islam did spread as a result of forced conversions. One well-known forced conversion helps to illustrate the fact that while a few Muslims endorsed forced coercion, they were repudiated by others. Maimonides, a well known Jewish scholar in Islamic Spain, was forced to convert to Islam after the Almohads removed the Almoravids from power. The Almoravid leadership was known for its strict interpretation of Islam, but it had still allowed Muslims, Christians and Jews to live together. Meanwhile, the Almohad leaders were much more severe. Maimonides left Almohad Spain, went to Egypt, and publicly declared himself a Jew. In response one of the most famous Muslim legal scholars of Egypt, Al-Qadi Al Fadil ĎAbd Al-Rahim, ruled that anyone forcibly converted to Islam could not be considered a Muslim.
Other instances of forced conversion have also evoked responses from Muslim scholars. This happened as two well known military leaders in 19th century West Africa forced conversions. Al-Hajj Umar Futiís policy of forced conversion was repudiated by the Kunti scholars of Timbuktu. Samory Toureís forced conversion policy was repudiated by the scholars of Kong, who even chose to be executed rather than endorse his policy. Some forced conversions also happened in the Horn of Africa during the 17th century wars between Christian Ethiopia and Muslim Somalis. In the eyes of ING, our affiliates, and most modern Islamic scholars these events are as tragic as Charlemagne forcing the Germanic tribes to convert to Christianity and the severity of the Spanish Inquisition. None of these forced conversions reflect the high calling of either Islamic or Christian doctrine.