Shang dynasty endured roughly from 1700 to 1027 B.C. The Shang dynasty （also called the Yin dynasty in its later stages） is believed to have been founded by a rebel leader who overthrew the last Xia ruler. Its civilization was based on agriculture， augmented by hunting and animal husbandry. Two important events of the period were the development of a writing system， as revealed in archaic Chinese inscriptions found on tortoise shells and flat cattle bones， and the use of bronze metallurgy. A number of ceremonial bronze vessels with inscriptions date from the Shang period； the workmanship on the bronzes attests to a high level of civilization.