Chinese 夏: from a name of the model emperor Yu (2205–2198 BC), who was also known as Xia Yu. His descendants adopted the first character of his name as a surname. Xia Yu was a gifted man, chosen by the previous emperor on the basis of merit. His son changed this type of meritbased succession, however, establishing the Xia dynasty (2205–1766 BC), the first dynasty in which the throne was passed on by heredity. The existence of the Xia dynasty has not been confirmed by archaeological evidence, but Chinese historians all accept its existence as fact.