 In 576, he was made the governor of Southern Yan Province (南兗州, roughly modern Yangzhou, Jiangsu).In 577, Northern Zhou destroyed Northern Qi and took over its territory.In winter 577, Emperor Xuan, believing that Northern Zhou's hold on Northern Qi's southern provinces was not yet secure, ordered Wu to launch a major attack on Pengcheng, making Wu's heir apparent Wu Rongzhao () his lieutenant.