The Origins of the Chinese Empire, to 220 C.E.

these cities, built by rulers to move troops and supplies, were traveled by traders transporting such items as metal tools and utensils, lacquered wood plates and boxes, silk, pottery, gems, salt, and lumber. A money economy emerged, using copper coins called cash, with center holes for stringing them together for counting and carrying. China's towns and cities were likewise linked into a large economic system . Trade between China and distant lands

A metal bell from the Zhou era.

was difficult and dangerous, but by the era's end commerce was conducted by sea with Southeast Asia and by land routes crossing Central Asia.

The Central Asian Connection
Central Asia, a vast expanse to China's north and west where the climate was too dry for farming (Map 2), was home mainly to pastoral nomads who grazed herds on its plateaus and plains. Skilled on horseback, the nomads occasionally attacked Chinese settlements to carry off goods and supplies, but they also spread commerce and useful knowledge. Some nomads, for example, exchanged their

Central Asian nomads connect China with other cultures Nomads and Chinese adopt horse riding and crossbows from each other

Iron tools and weapons spread to China, enhancing farming and warfare

hides, wool, and horses for Chinese silk, pottery, metalware, and wood products and then traded these items with other societies across Central Asia. Over time, connections with the nomads, and through them with other Eurasian societies, had major impacts on China.
Nomadic connections, for example, transformed Chinese warfare in the Eastern
Zhou era. From the nomads Chinese armies adopted horseback riding, replacing chario- teers with mounted riders who moved and maneuvered more quickly. The nomads in turn began using the crossbow, a Chinese invention that could kill