Started when China's main trade was silk. Originally, they only traded within China, but overtime, the trade route began to grow larger and larger. It ended up being 7000 miles long and spread through China, Central Asia, Northern India, and the Parthian and Roman Empires. Trading silk played only a minor role in China's economy. Through trading silk, China exposed their religions and cultures to where they traded it.By 760 AD, trade along the Silk Road declined.