The expansion of the Muslim Empire in the years following the Prophet Muhammad’s death led to the creation of the caliphates, occupying a vast geographical area and conversion to Islam was boosted by missionary activities particularly those of Imams, who easily intermingled with local populace to propagate the religious teachings. These early caliphates, coupled with Muslim economics and trading and the later expansion of the Ottoman Empire, resulted in Islam’s spread outwards from Mecca towards both the Atlantic and Pacific Oceans and the creation of the Muslim world. Trading played an important role in the spread of Islam in several parts of the world, notably southeast Asia.
Muslim dynasties were soon established and subsequent empires such as those of the Abbasids, Fatimids, Almoravids, Seljukids, Ajuran, Adal and Warsangali in Somalia, Mughals in India and Safavids in Persia and Ottomans in Anatolia were among the largest and most powerful in the world. The people of the Islamic world created numerous sophisticated centers of culture and science with far-reaching mercantile networks, travelers, scientists, hunters, mathematicians, doctors and philosophers, all contributing to the Golden Age of Islam.
The Byzantine Empire, also referred to as the Eastern Roman Empire, was the continuation of the Roman Empire in the East during Late Antiquity and the Middle Ages, when its capital city was Constantinople (modern-day Istanbul, which had been founded as Byzantium). It survived the fragmentation and fall of the Western Roman Empire in the 5th century AD and continued to exist for an additional thousand years until it fell to the Ottoman Turks in 1453. During most of its existence, the empire was the most powerful economic, cultural, and military force in Europe. Both “Byzantine Empire” and “Eastern Roman Empire” are historiographical terms created after the end of the realm; its citizens continued to refer to their empire as the Roman Empire (Greek: Βασιλεία τῶν Ῥωμαίων, tr. Basileia tôn Rhōmaiōn; Latin: Imperium Romanum), or Romania (Ῥωμανία), and to themselves as “Romans”.