Wang Zhaojun was one of the four China’s ancient beauties, and is perhaps the best known of China’s “political brides”.
According to this article, during the reign of Emperor Yuan (48-33BC), Wang Zhaojun, entered the imperial harem willingly to save her father, a scholar-official, from persecution.
Only when Wang Zhaojun was on the point of departure did the Emperor set eyes on her. Much to his dismay, he realized his terrible mistake that Wang Zhaojun was in fact the loveliest woman in his harem. He wanted to find a substitute for her; however, it was too late for the Emperor to change his mind. The fate of Wang Zhaojun had however been sealed. In anguish and sorrow, he parted with Wang Zhaojun. The court artist Mao Yanshou was subsequently put to death for deceiving the Emperor.
According to this Wikipedia article, Wang Zhaojun became a favourite of the Hun Prince, giving birth to two sons and at least one daughter. When the Hun Prince died, Wang Zhaojun requested to return to China. Then Han Emperor, however, ordered that she follow the Hun levirate custom and become the wife of the next Chanyu, the oldest brother next her husband.
According to other legends, she commits suicide after her husband’s death as her only resort in order to avoid marrying his son.