Unity of Commerce and Language

Although the regions of the Islamic world were culturally and politically diverse, they maintained a measure of unity through trade networks and language. Their principal bond was Arabic, the language of the Qur’an. At once poetic and sacred, Arabic was also the language of commerce and government from Baghdad to Córdoba. Moreover, despite political differences, borders were open. The primary reason for these open borders was Islam itself, but the openness extended to non-Muslims as well.

The commercial activities of the Tustari brothers, Jewish merchants from southern Iran, are a good example. By 1026, they had established a flourishing business in Egypt. Informal contacts with friends and family allowed them to import fine textiles from Iran to sell in Egypt and to export Egyptian fabrics to sell in Iran. The Tustari brothers held the highest rank in Jewish society and had contacts with Muslim rulers. At the same time, commercial networks even more vast than those of the Tustari family were common. Muslim merchants brought tin from England; salt and gold from Timbuktu in west-central Africa; amber, gold, and copper from Rus; and slaves from every region.