A canonical Chinese pantheon is difficult to establish. There is no developed heavenly family such as the ones we find in Norse or Greek mythology. Even the supreme being changes at various stages in Chinese history. In the early Shang period (1600–1300 B.C.E.) the great god was Shang Di. Later, during the Zhou Dynasty, he was Tian (Heaven) Di. The term tiandi represents the union of sky and earth. Tian Di was for some the same being as Shang Di, Shang Di being the deity’s name, Tian being more of an abstraction. Another supreme deity name is Di Jun of the Yin people in eastern China. Much later, in the Common Era, the supreme deity was Yu Di, the Jade Emperor. For Daoists the supreme being is T’ai. The root meaning for many of these names is “sky,” the place of the gods. Because of conflicts between the many ethnic groups in China, the pantheon was repeatedly rearranged to fit political realities and the dominance of particular groups. When the Shang and Zhou united, Di Ku became the supreme deity and the mothers of the founders of the two groups became his wives. During the so-called Warring States period (475–221 B.C.E.) of the Zhou Dynasty, another attempt was made to create a new pantheon. Zhurong had been the divine founder of the Chu people; his name was changed to Zhuanxu. For some, his son was the more famous Yu, who is sometimes treated more as a human hero-type than as a god. The confusion of heroes with gods is a constant element in the Chinese pantheonic vision, as in the case of several of the grouping known as the Five August Emperors. There are several important goddesses in the Chinese pantheon, the most important of whom are Nuwa and, under Buddhist influence, Guanyin.