The reason is that Fu Jian has completed the unification of the north, leaving only the corner of the Eastern Jin Dynasty, and Fu Jian thinks he is strong enough to defeat the Eastern Jin Dynasty. Under years of war, the country has been unable to make ends meet, and those countries and nations that have just been conquered have not surrendered. At this time, going south is bound to be rebelled by these ethnic groups. Many ministers advised Fu Jian not to attack the Eastern Jin Dynasty, but Fu Jian thought that he was the master of the world and it was necessary to unify the world. Moreover, he wanted the Eastern Jin Emperor to be his servant and the Prime Minister to be his servant. Fu Jian fantasized about his own master all day and forgot his biggest enemy at present. Both Dao An and Wang Meng persuaded Fu Jian, but Fu Jian always enjoyed the fruits of victory.

On the unification of the Northern Expedition, Fu Jian did not encounter too much setbacks, and felt that his country was invincible. After Fu Jian got Wang Meng, Wang Meng tried his best to assist Fu Jian, and there were Jie and Xianbei dynasties in the north. Under the planning of Wang Meng, the chaos in the north was ended in a short time, and the territory of the Qin Dynasty was expanded. After the unification of the north, Wang Meng also died. Fu Jian was very sad to hear that, which made the relationship between monarch and minister enviable. After Wang Meng's death, he was honored as? King Wuhou? . A few years later, Fu Jian began to want to occupy the Eastern Jin Dynasty in the south, but was opposed by court ministers. Privately, Fu Jian consulted his brother Fu Rong about going south, but he met with stubborn resistance from Fu Rong. Fu Rong always advised Fu Jian not to go south easily. Now the biggest enemies are Xianbei people and Miao people. Unfortunately, Fu Jian still didn't take these words to heart.

Fu Jian wants to be the master of the world, so he wants to speed up the unification of the world. After Fu Jian had his own huge empire, he began to celebrate the Eastern Jin Dynasty. He wants to be the overlord of the world day and night, and he also wants the Eastern Jin Emperor of the Central Plains to be his slave. Under his fantasy, he gradually deviated from the right path and finally led to disaster.

After Fu Jian has a powerful country, it wants national reunification and realizes its dream.