With Dong Zhuo gone and a weakened Emperor Xian in exile, a power vacuum has opened in the lands ruled by the Han Dynasty. Before long, Cao Cao, Yuan Shao, and Lv Bu are jockeying for position in the race to rule the nation. Provinces will change hands, allegiances will shift, and the law of the land will change in ways no one could have imagined.
Cao Cao understands something that the others fail to grasp: Even though the Han Dynasty has little real power, the perception of imperial power among the people remains very strong, because at the end of the day everyone understands that they are subjects of the dynasty. That's what drives Cao Cao's decision to come to the aid of the exiled emperor: now that Cao Cao has amassed tremendous power and an enormous army, all he needs to become the most powerful man in China is the perception of authority. Allying himself with the emperor will not only endear him to the people, it will make it easier for him to manipulate the other lords into fighting one another, thus ridding Cao Cao of enemies and clearing the way for him to eventually inherit the throne.
