The Han Dynasty army regularly policed the trade route against nomadic bandit forces generally identified as Xiongnu. Han general Ban Chao led an army of 70,000 mounted infantry and light cavalry troops in the 1st century CE to secure the trade routes, reaching far west to the Tarim Basin. Ban Chao expanded his conquests across the Pamirs to the shores of the Caspian Sea and the borders of Parthia. It was from here that the Han general dispatched envoy Gan Ying to Daqin (Rome). The Silk Road essentially came into being from the 1st century BCE, following these efforts by China to consolidate a road to the Western world and India, both through direct settlements in the area of the Tarim Basin and diplomatic relations with the countries of the Dayuan, Parthians and Bactrians further west. The Silk Roads were a "complex network of trade routes" that gave people the chance to exchange goods and culture.