In what ways did long distance commerce act as a motor of change in premodern world history?

Long distance commerce acted as a motor of change in pre-modern world history in several ways. First, it ultimately led to the creation of powerful states as the trade helped enrich economic situation. In the process, it also increased the gap between the rich and poor. Second, it led to the spread of religions such as Islam and Buddhism. This is because people carried with them their religion and beliefs. The trade also brought about disastrous effects such as the spread of diseases. It also made possible the exchange of technology, plants, and animals between different regions. Furthermore, new civilizations were founded along the roads where merchants stopped. 

Treated as a slave is cruel and harsh