Qi and Wang Lin before preventing the forces of Northern Zhou from entering the South at Yueyang. Furthermore, through Emperor Wen's extensive efforts at good governance, the economic situation of the South was greatly improved, restoring his kingdom's national strength. 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. In a stroke of fortune, Northern Zhou's Emperor Wu suddenly died and his general Yang Jian attempted to take the throne. This stopped the southern advance of the Northern Troops. The respite was short though as after Yang Jian defeated his rival General Yuchi Jiong, he usurped the throne from Emperor Jing of Northern Zhou and established the Sui dynasty, crowning himself Emperor Wen of Sui. He proceeded to invade the south to reunify China. Emperor Xuan had just died and his incompetent son Chen Shubao (Houzhu of Chen) took power. He was licentious and wasteful, resulting in chaos and corruption in the government; many officials heavily exploited the people, causing great suffering. In planning tactics to defeat the Chen dynasty, Emperor Wen of Sui took the suggestion of his general Gao Jiong and waited until the South were harvesting their crops to entirely burn the farmland, crippling the strength of the Chen dynasty. In 588, Emperor Wen of Sui sent his son Yang Guang (who would