The spread of Islam spans almost 1,400 years. The early Muslim conquests that occurred following the death of Muhammad in 632 CE led to the creation of the caliphates, expanding over a vast geographical area; conversion to Islam was boosted by Arab Muslim forces expanding over vast territories and building imperial structures over time. Most of the significant expansion occurred during the reign of the rāshidūn ("rightly-guided") caliphs from 632 to 661 CE, which were the first four successors of Muhammad. These early caliphates, coupled with Muslim economics and trading, the Islamic Golden Age, and the age of the Islamic gunpowder empires, resulted in Islam's spread outwards from Mecca towards the Indian, Atlantic, and Pacific Oceans and the creation of the Muslim world. The Islamic conquests, which culminated in the Arab empire being established across three continents (Asia, Africa, and Europe), enriched the Muslim world, achieving the economic preconditions for the emergence of this institution owing to the emphasis attached to Islamic teachings. Trade played an important role in the spread of Islam in some parts of the world, such as Indonesia. During the early centuries of Islamic rule, conversions in the Middle East were mainly individual or small-scale. While mass conversions were favored for spreading Islam beyond Muslim lands, policies within Muslim territories typically aimed for individual conversions to weaken non-Muslim communities. However, there were exceptions, like the forced mass conversion of the Samaritans.
Muslim dynasties were soon established and subsequent empires such as those of the Umayyads, Abbasids, Mamluks, Seljukids, and the Ayyubids were among some of the largest and most powerful in the world. The Ajuran and Adal Sultanates, and the wealthy Mali Empire, in North Africa, the Delhi, Deccan, and Bengal Sultanates, and Mughal and Durrani Empires, and Kingdom of Mysore and Nizam of Hyderabad in the Indian subcontinent, the Ghaznavids, Ghurids, Samanids in Persia, Timurids, and the Ottoman Empire in Anatolia significantly changed the course of history. The people of the Islamic world created numerous sophisticated centers of culture and science with far-reaching mercantile networks, travelers, scientists, hunters, mathematicians, physicians, and philosophers, all contributing to the Islamic Golden Age. The Timurid Renaissance and the Islamic expansion in South and East Asia fostered cosmopolitan and eclectic Muslim cultures in the Indian subcontinent, Malaysia, Indonesia and China. The Ottoman Empire, which controlled much of the Middle East and North Africa in the early modern period, also did not officially endorse mass conversions, but evidence suggests they occurred, particularly in the Balkans, often to evade the jizya tax. Similarly, Christian sources mention requests for mass conversions to Islam, such as in Cyprus, where Ottoman authorities refused, fearing economic repercussions.
