Following the death of Emperor Wen, his son, the weak-willed Chen Bozong, took power and became Emperor Fei of Chen. His uncle, Chen Xu, after essentially controlling the country through his short reign, eventually deposed him and took power as Emperor Xuan of Chen. At that time, the Northern Zhou intended to conquer Northern Qi and thus invited the Chen dynasty to help. Emperor Xuan agreed to help because he wanted to recover the lost territories south of the Huai River. In 573, he sent general Wu Mingche to assist the effort; in two years, he managed to recover he lost territories south of the Huai River. At the time, Northern Qi was in a precarious situation with little military strength and Emperor Xuan could have taken advantage of the opportunity to entirely defeat Northern Qi. However, he only wanted to protect his territories south of the Huai River. Northern Zhou instead took advantage of Northern Qi's weakness and following their defeat of Northern Qi, in 577, they sent troops to the territories south of the Huai River, where they decisively defeated the Chen dynasty forces. The Chen dynasty was in imminent danger.