‘Environment and empires’ surveys the geographic character of the silk road. The silk road was a not a single route, and traded in more than silk. Similarly, it was more than just a route between China and the Mediterranean, it shaped and interacted with the people and empires of south and central Asia. A land route was necessary, as the rivers of central Asia offer no access to the sea. The silk road has long been a conduit for nomadic empires, whose ease of movement is shaped by their environment. Faiths, scripts and knowledge spread through religious networks, helping integrate the Eurasian continent through the exchange of objects and ideas.