In the first year of Jian 'an (196), Cao Cao moved Emperor Xian of Han Dynasty and his courtiers to Xu County, his base area, and renamed it Xuchang, thinking that he was the capital city, and he became a general himself, thus getting rid of Yang Feng's control of the Han Dynasty and firmly holding Xian Di in his own hands.
Cao Cao's position has been rising while assisting Emperor Xian of Han Dynasty. Day after day, Cao "supported the emperor and made his ministers". Cao Cao started the war to unify the north after "seizing the emperor to make the princes".
In Jian 'an 12 (207), Cao Cao basically unified the north. After years of war, Cao Cao's power soared and his control over the court became tighter and tighter.
Cao Cao, the prime minister of the Han Dynasty and Wang Wei, was called a Han thief because he initiated the act of "seizing the emperor to make the princes". He also killed the Fu Empress and Dong Guiren of Liu Xie, Emperor Wu of the Han Dynasty, and the two princes born after Fu, but he did not claim to be the emperor until his death, and only let his son Cao Pi claim to be the emperor on behalf of the Han Dynasty.
Extended data:
Cao Cao pacified Lu Qiang, wiped out Wuhuan, suppressed Xiongnu and subdued Xianbei, so that he could not take advantage of the troubled times at the end of the Han Dynasty to enter the Central Plains, and his achievements in foreign wars were no less than those of any famous emperor of the unified dynasty.
At the same time, Cao Cao has a greater responsibility to kill prisoners and maim the people and hurt scholars. Yanzhou worked as a shepherd and slaughtered hundreds of thousands of people in Xuzhou cities.
In the post-war era, Guandu raped and killed 70,000 soldiers, including old friends such as Yu Xun and Cui Yan, so Yu You and Lou Gui could not die. These are indelible guilt. Not two people are the first offenders, but it is a thousand-year crime, and it is famous all over the world, and it is also full of slander.
Holding the emperor to command the princes is holding the emperor and giving orders in his name. Now the metaphor is to command others according to their own meaning in the name of leadership. Moreover, this word is considered as a patent of Cao Cao in modern times.
References:
Baidu encyclopedia-Cao Cao