after Yang Yong, and he had at least one older sister, Yang Lihua, who became the wife of Emperor Wu's crown prince Yuwen Yun (the later Emperor Xuan) in 573. He was considered handsome and intelligent in his youth, and of Yang Jian's and Duchess Dugu's sons, they favored him the most. Sometime during Northern Zhou, on account of Yang Jian's achievements, he was created the Duke of Yanmen. In 580, Yang Jian seized power as regent after Emperor Xuan's death. In 581, he had Emperor Xuan's son (by the concubine Zhu Manyue), Emperor Jing, yield the throne to him, ending Northern Zhou and establishing Sui Dynasty as its Emperor Wen. Emperor Wen created Yang Yong crown prince and created his other sons imperial princes. Yang Guang thus received the title of Prince of Jin. As Prince of Jin Also in 581, Emperor Wen made Yang Guang the commandant at Bing Province (并州, roughly modern Taiyuan, Shanxi), in charge of the provinces north of the Yellow River. In 582, Emperor Wen set up a branch of the executive bureau of his government (尚書省, Shangshu Sheng) at Bing Province and made Yang Guang its head. He made the official Wang Shao () the deputy head and had him assist Yang Guang. Later in 582, Emperor Wen took a daughter of his vassal Emperor Ming of Western Liang (Xiao Kui) to be Yang Guang's wife and princess. It was said that Yang Guang loved and respected her. In 584, after some Sui military and diplomatic victories, Tujue's Shabolüe Khan Ashina Shetu submitted to Sui. Yang Guang suggested to Emperor Wen that he rejected Ashina Shetu's overture and launch a major attack on Tujue, but Emperor Wen refused. In 585, with Ashina Shetu under attack from one of his subordinate khans, the Datou Khan Ashina Dianjue, Emperor Wen in fact sent Yang Guang to aid Ashina Shetu. In 588, Emperor Wen moved Yang Guang's headquarters to Shouchun (壽春, in modern Lu'an, Anhui), and made him the commandant there as well as the head the branch of the executive bureau established there. In winter 588, Emperor Wen launched a major attack on the rival Chen dynasty. Yang Guang, his brother Yang Jun, and the general Yang Su were in command of the three main prongs of the operation, with Yang Guang in command of the eastern prong as well as the overall operation. The