[3] Prior to Yang Yuling's becoming prominent, he served a term as the sheriff of Jurong County (句容, in modern Zhenjiang, Jiangsu).
The governor of Zhexi Circuit (浙西, headquartered in modern Zhenjiang), which Jurong was in, Han Huang (who would, eventually, become a chancellor), was impressed with Yang Yuling.
At that time, Han was looking for a husband for his daughter, and he stated to his wife Lady Liu, "I have met many people, but none appears as primed for honors and long life as Mr. Yang.
[1] Later, during the reign of Emperor Dezong's grandson Emperor Xianzong, it was said that because Yang Sifu became well known by the chancellor Wu Yuanheng (along with Pei Du and Liu Gongchuo (柳公綽)), Wu, while later serving as the military governor of Xichuan Circuit (西川, headquartered in modern Chengdu, Sichuan), invited them to serve on his staff.
At that time, the former chancellor Zheng Yuqing was commissioned to revise the ceremonies, and at his request, Yang was made his secretary for the task.
Emperor Xianzong issued an edict in which he opined that there could be no impropriety since Yang Yuling was not his son's superior.
In 833, at which time LI Zongmin was a chancellor, Yang Sifu was recalled to government service to serve as Shangshu Zuo Cheng (尚書左丞), one of the secretaries general of the executive bureau.
[8] In 837, Yang was recalled to the capital to serve as deputy minister of census, as well as the director of the salt and iron monopolies.
[1] In 838, he was made, along with Li Jue, chancellors de facto with the designation Tong Zhongshu Menxia Pingzhangshi (同中書門下平章事).
Further, as Yang advocated for Li Zongmin, who had been exiled, to be moved closer to the capital, and Chen and another chancellor, Zheng Tan, both opposed.
It was said that from this point, Yang and Li Jue were often in a factional struggle against Chen and Zheng, causing Emperor Wenzong to be unable to rule on their proposals easily.
Li Jue responded, "Your Imperial Majesty had told me previously that an Emperor should select chancellors, not suspect them."
Li Jue, offended, responded, "Chen Yixing is obviously suspecting that there are chancellors who are stealing power from Your Imperial Majesty.
Emperor Wenzong subsequently sent a eunuch to comfort him, and Zheng partially apologized, stating, "Your subject is foolish.
[1] When the official Wei Wen (韋溫) argued that capable administrators should not be given high positions unless they had honored origins, Yang pointed out that this would lead to incompetence in the government, like what happened during Jin dynasty.
[9] Soon after Emperor Wuzong took the throne, Yang Sifu was removed from his chancellor position and made the minister of civil service affairs (吏部尚書, Libu Shangshu), as Emperor Wuzong knew that Yang and Li Jue, who was likewise removed, did not support him.
[1] Meanwhile, Qiu Shiliang, who resented Liu Hongyi and Xue Jileng deeply, continued to make allegations against them, and in 841, Emperor Wuzong, believing in those allegations, ordered them to commit suicide, and also sent eunuchs to Hunan's capital Tang Prefecture, and Gui Prefecture (桂州, in modern Guilin, Guangxi), where Li Jue was serving as the governor of Gui District, to order Yang and Li Jue to commit suicide as well.
[10] Apparently, soon thereafter, Emperor Xuānzong further ordered Yang recalled to serve as the minister of civil service affairs.