History of the world
Whether in prehistoric or historic times, people always needed to be near reliable sources of potable water. Settlements developed on river banks as early as 3000 BCE in Mesopotamia, on the banks of Egypt's Nile River, in the Indus River valley, and along China's rivers. As farming developed, grain agriculture became more sophisticated and prompted a division of labour to store food between growing seasons. Labour divisions led to the rise of a leisured upper class and the development of cities, which provided the foundation for civilization. The growing complexity of human societies necessitated systems of accounting and writing.
Cradle of civilization
The earliest traditional Chinese dynasty for which there is both archeological and written evidence is the Shang dynasty (1600 to 1046 BC). Shang sites have yielded the earliest known body of Chinese writing, the oracle bone script, mostly divinations inscribed on bones. These inscriptions provide critical insight into many topics from the politics, economy, and religious practices to the art and medicine of this early stage of Chinese civilization. Some historians argue that Erlitou should be considered an early phase of the Shang dynasty. The U.S. National Gallery of Art defines the Chinese Bronze Age as the period between about 2000 and 771 BC; a period that begins with the Erlitou culture and ends abruptly with the disintegration of Western Zhou rule. The Sanxingdui culture is another Chinese Bronze Age society, contemporaneous to the Shang dynasty, however they developed a different method of bronze-making from the Shang.