The Bronze Age is the period when humans learned to use bronze to create more advanced types of tools and weapons. Prior to this period, people mainly relied on objects made of stone, clay and wood. In China, the Bronze Age began around 4,000 years ago and spanned the Xia, Shang, and Zhou dynasties. Based on societal demands, large quantities of bronze wares were manufactured and used in rituals, agricultural production, military applications and other areas.