reign name of the Chinese emperor who overthrew the Xia dynasty (c. 2070–c. 1600 BC) and founded the Shang (Shang dynasty), the first historical dynasty ( c. 1600–1046 BC, though the dating of the Shang—and hence also of the Tang emperor's founding of it—have long been the subject of much debate).

As a historical figure, Tang was apparently a scion of a noble family. According to legend, he was a descendant of the mythical sage-king Huangdi (the “Yellow Emperor”). Tang is also said to have revolted against the evil last ruler of the Xia dynasty after reading on the shell of a tortoise a prophecy that he would do so.

Revered as a humane and generous ruler, Tang is said to have offered himself as a sacrifice to Heaven during a drought. Rain fell before the ceremony ended, however, and he was spared. He is usually represented as a nine-foot-tall, white-faced, whiskered man with a pointed head, six-jointed arms, and a body markedly larger on one side than on the other.