Part 3: Postclassical Civilizations, c. 600–c. 1200

In many parts of the world, the decline of classical civilizations was marked by a century or more of declines in trade, intellectual innovation, and social stability. However, new centralized states that promoted peace and prosperity emerged to replace them. Throughout Afro-Eurasia, trade intensified after 600 as networks of exchange widened and became more profitable. The Silk Roads, the Indian Ocean trade networks, and the trans-Saharan trade routes were brimming with items such as porcelain, ivory, teakwood, spices, and silk. These networks of exchange also provided ways for technology and ideas to move from one culture to another. More and more regions became familiar with the compass, the astrolabe, new forms of credit, paper money, and new religious beliefs.

However, all of this exchange came with a high price. Deadly diseases also spread along these same pathways.

Afro-Eurasia and the Americas remained separate, but people in Mesoamerica and the Andes Mountains experienced similar developments. The growth of more centralized states in each region also promoted trade and the spread of ideas.