The volume of long-distance trade dramatically increased between 600 C.E. and 1450 C.E. Luxury items of high value, such as silk and precious stones, were typically transported over land routes. Merchants used sea routes to transport bulkier commodities, such as steel, stone, coral, and building materials.
The Silk Road trade linked the Eurasian land mass. Trans-Saharan trade connected West Africa to the Mediterranean and Islamic Empire. The Indian Ocean trade linked China, Southeast Asia, India, Arabia, and East Africa. The Mediterranean Sea trade linked Europe with goods from the Islamic Empire and Asia.
Because of this global exchange, and because of increased agricultural productivity and slightly warmer global temperatures between 800 C.E. and 1300 C.E., cities located along trade routes grew substantially. For instance, Melaka, a city on the coast of the Malay Peninsula in Southeast Asia, served as an important port city on the Indian Ocean. It became the Sultanate of Melaka, an Islamic state, as Muslim traders settled into the region and spread Islam in the early fifteenth century C.E. Melaka maintained a safe environment for trade, welcomed merchants, and charged reasonable fees. As a result, it thrived in this interconnected world, along with cities like Hangzhou in China, Samarkand in Central Asia, Baghdad in modern-day Iraq, Kilwa in East Africa, Venice in Italy, and Timbuktu in Mali, Africa.
Although cities generally increased in size between 600 C.E. and 1450 C.E., military invasions, diseases, and reduced agricultural productivity caused some cities to experience periods of significant economic decline.
Merchants set up their own communities, where they often influenced the dominant culture along trade routes. For example, Muslim merchants in the Indian Ocean region, Chinese merchants in Southeast Asia, and Jewish merchants in the Mediterranean settled in diaspora communities in trade cities.