Asia
The coastal periphery was home to some of the world's earliest known civilizations, each of them developing around fertile river valleys. The civilizations in Mesopotamia, the Indus Valley and the Yellow River shared many similarities. These civilizations may well have exchanged technologies and ideas such as mathematics and the wheel. Other innovations, such as writing, seem to have been developed individually in each area. Cities, states and empires developed in these lowlands.
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.