 By new year 580, nearly all of the territory north of the Yangtze had fallen to Northern Zhou, leading to a large wave of refugees who fled across the Yangtze to Chen territory.In summer 580, Northern Zhou's Emperor Xuan died suddenly, and his father-in-law Yang Jian seized power as regent.The generals Yuchi Jiong rose against Yang, and he was joined by the generals Sima Xiaonan (司馬消難) and Wang Qian (王謙).