At the beginning of the siege , Cao Cao was fighting Sun Quan in Ruxukou .
After he returned to the city of Ye , he was busy launching the establishment of the principality of Cao Wei .
At the beginning of the siege , Cao Cao was fighting Sun Quan in Ruxukou , and after he returned to the city of Ye , he was busy launching the establishment of the principality of Cao Wei .