The earliest known written records of the history of China date from as early as 1250 BC, from the Shang dynasty (c. 1600–1046 BC), during the reign of king Wu Ding, referred to in the records as the twenty-first King of Shang. Ancient historical texts such as the Book of Documents (early chapters, 11th century BC), the Bamboo Annals (c. 296 BC) and the Records of the Grand Historian (c. 91 BC) describe a Xia dynasty before the Shang, but no writing is known from the period, and Shang writings do not indicate the existence of the Xia. The Shang ruled in the Yellow River valley, which is commonly held to be the cradle of Chinese civilization. However, Neolithic civilizations originated at various cultural centers along both the Yellow River and Yangtze River. These Yellow River and Yangtze