禹貢
According to the "Rongcheng Shi" bamboo slips from the Warring States period, the "Yu Gong" from the Han dynasty and various other sources, Yu the Great divided the world into the Nine Provinces in prehistoric times, one of them Xu. The "Yuanhe Xingzuan", a Tang dynasty compilation of information on the origins of Chinese surnames, as well as the "Tongzhi", a Southern Song dynasty historical book, also state that Yu enfeoffed Ruomu, grandson of the mythological emperor Zhuanxu, as lord of Xu around 2100 BC. In turn the Xu peoples were supposed to be Ruomu's descendants. Furthermore, it was claimed this Xu state or province had originally occupied the entire area between the Huai and Yellow River. No contemporary evidence exists to verify this information and the oldest literary sources available, the oracle bones of the Shang dynasty, do not mention such an empire. As result, the stories of Xu's foundation remain legendary.