In his proclamation of victory to Emperor Xian , Cao Cao claimed to have killed 70,000 enemy troops .
Some of these men had feigned surrender so they could escape later , thus Cao Cao had these men buried alive .
In Cao Cao 's proclamation of victory to Emperor Xian , Cao Cao claimed to have killed 70,000 enemy troops .
Some of these men had feigned surrender so they could escape later , thus Cao Cao had these men buried alive .