He drew ire from his parents for wastefulness (which Emperor Wen disliked) and having many concubines (which Empress Dugu disliked), while his younger brother, Yang Guang, whom Emperor Wen and Empress Dugu thought lacked these faults, was favored by them.
During this time, Yang Yong served as a low-level official in Northern Zhou's imperial administration.
After defeating the general Yuchi Jiong, who rose against him, he had Yang Yong created the Duke of Changning and the commandant of Luoyang, with authority over all of the old territory of Northern Qi (which Emperor Xuan's father Emperor Wu destroyed in 577.
In the Book of Sui, Yang Yong was described as a studious and handsome gentleman who was known for his gracious demeanour, straightforwardness and generosity, and was respected by many.
The plot was discovered, and Lu Ben and his associates were deposed, but Yang Yong was not punished.
In winter 582, Emperor Wen, anticipating an attack from Tujue during the construction of his new capital Daxing, near Chang'an, had Yang Yong command troops and briefly posted at nearby Xianyang to defend the potential Tujue attack.
Subsequently, in summer 586, Emperor Wen again had Yang Yong posted to Luoyang, with authority over the surrounding provinces.
Once, when Yang Yong made a highly decorated set of armor, Emperor Wen rebuked him, sending him an undecorated sword that Emperor Wen himself employed, as well as a box of miso, to remind him that prior to becoming crown prince, he had to settle for common items such as those.
Crown Princess Yuan, who did not have any sons with Yang Yong, died suddenly in 591, apparently from a heart ailment, but both Emperor Wen and Empress Dugu suspected foul play, and Empress Dugu particularly rebuked him.
After Crown Princess Yuan's death, Consort Yun became the effective mistress over the Crown Prince's palace, and she and the other concubines bore Yang Yong 10 sons in total, which made Empress Dugu exceedingly displeased, as she was even more displeased at men having children with their concubines.
Traditional historians allege (but admit that they did not have conclusive proof) that while Emperor Wen was growing ill, Yang Guang tried to rape Consort Chen.
Parents Consort and their respective issue(s): Yang Yong is portrayed by Hong Kong actor Liu Kai-chi in TVB's 1987 series The Grand Canal (大運河)