In the last years of Nan'an, Emperor Ai was incompetent and under the dictatorship of eunuchs. The people were in dire straits and uprisings continued. Dong Qing, his relative, took the opportunity to kill the emperor and establish himself. However, in order to stabilize the throne, Dong Qing almost killed all the royal family members. The excessive killings caused dissatisfaction in the world. There was chaos in the nine states, warlords were everywhere, and wars continued. Dong Qing also died in the warlords' melee.
Seven years after Dong Qing's Rebellion, the world was divided into four parts, and the land of Kyushu also ushered in a brief period of peace.
Among them, the regime of Liu Ying, the former Fengzhou Mu, who lived all the way to the southwest, took the lead in proclaiming the emperor, named the country Zhou, and established Suiye as the capital; in the northwest, the regime of Tang Yishou, the former Yuzhou Si, proclaimed the emperor in August of the same year, named the country Feng, and established Yujing as the capital; occupying the southeastern area was the uprising army headed by Fan Yue, who raised troops in Hongliang, also known as the Red Liang Army;
The king of Yang'an was a descendant of the former royal family and lived in the north. Seeing the chaos in Kyushu, he took advantage of the situation and established himself on his own. He extended the country's name to An and made Yang'an the capital. It was called Bei'an in history and also called Hou'an.