Later, during the Han dynasty, these tables were used by prominent families to glorify themselves and sometimes even to legitimize their political power. For example, Cao Pi, who forced the abdication of the last Han emperor in his favor, claimed descent from the Yellow Emperor. Chinese emperors sometimes passed their own surnames to subjects as honors. Unlike European practice in which some surnames are obviously noble, Chinese emperors and members of the royal family had regular surnames except in cases where they came from non-Han ethnic groups. This was a result of Chinese imperial theory in which a commoner could receive the Mandate of Heaven and become emperor. Upon becoming emperor, the emperor would retain his original surname. Also as a consequence, many people also had the same surname as the emperor, but had no direct relation to the royal family.