For one thousand years, from 600 to 1600 ce, the Islamic world was one of the most dynamic and expansive global civilizations. It originated amongst nomadic peoples in the desert of the Arabian Peninsula. The youngest of the world religions was at the base of a powerful empire that extended from India to Spain. During its growth, the Islamic civilization incorporated very diverse traditions of Arab, Persian, Turkish, Greek-Roman, South Asian and African origin. Expansion hampered a central government and the Islamic world disintegrated into diverse political units; this did not hinder the continued expansion of Islam far beyond the borders of the original Arabian empire. Despite the existence of strong ideological differences, the shared religious culture remained a powerful uniting force in what some call ‘the first global civilization’ (in a Eurasian context). What made this cultural force so strong? First, the faith had omnipresent networks. They nurtured a generally-shared commitment, with the same texts, the same practices and identical language tied into a truly cosmopolitan web. Second, intense exchange networks of goods, knowledge and technology connected the diverse regions and political entities. Muslim traders, especially Arabs and Persians, were dominant players in the extensive Eurasian networks, supported by new techniques in banking and business practices. Technical innovations – including water management, weaponry and transportation – spread quickly. Third, strong cultural innovations in literature, poetry, sciences, medicine and philosophy developed in this world. This triple connectedness gave the Islamic civilization great internal coherence across regional boundaries. This indicates that civilization as a cultural concept has a significance of its own. How can we explain this?