Traces the spread of religions and cultures along the trans-Eurasian trade routes over a period of more than two millennia. Indian, Iranian, Semitic, and Mediterranean ideas all followed the same trajectory through Central Asia to China and beyond, picking up additional elements and sometimes being radically transformed along the way. This age-old pattern shows how the transmission of culture and the development of economic networks have always been inextricably linked, laying a precedent for the globalizing trends seen today