After Empress Wenxian [(i.e., Empress Dugu)] died, Emperor Wen greatly favored both Consort Chen (the Lady Xuanhua) and Consort Cai (the Lady Ronghua). Consort Chen was the daughter of Emperor Xuan of Chen. Consort Cai was from Danyang [(丹楊, in modern Nanjing, Jiangsu)]. The Emperor grew ill at Renshou Palace, and was bedridden. Yang Su, the left head of the Shangshu Sheng, Liu Shu [(柳述)], the minister of defense [(Emperor Wen's son-in-law as the husband of his daughter Yang Awu (楊阿五) the Princess Lanling)], and Yuan Yan [(元巖)] the court administrator, were all attending to him. The Emperor ordered the Crown Prince to enter the palace to stay at Dabao Hall [(大寶殿)]. The Crown Prince thought that precautions needed to be taken in case of the Emperor's death, and therefore he personally wrote a secret note to inquire of Yang Su what precautions to take. Yang Su wrote a return note detailing his security precautions, but by error the palace attendants delivered it to the Emperor. The Emperor was greatly displeased. Further, one morning, Consort Chen was going to the latrine. Yang Guang could not resist her beauty, and grabbed her, wanting to have sexual relations with her. She resisted and fled back to the Emperor. The Emperor was surprised by her anxiety and asked her; she shed tears and stated, "The Crown Prince was being indecent to me." The Emperor was shocked and angry, pounding the bed and stating, "Animal! How can I give him the important affairs? Dugu destroyed me!" He then summoned Liu and Yuan, telling them, "Summon my son!" They were about to summon the Crown Prince when he clarified, "Yang Yong!" Liu and Yuan left the palace to write the edict. When Yang Su heard this, he reported to the Crown Prince, and thereafter an edict of the Emperor was forged to arrest Liu and Yuan and detain them at the jail at the Supreme Court. The guards of the Eastern Palace [(i.e., the Crown Prince's guards)] were summoned to take over security from the Renshou Palace guards. Security measures were instituted to disallow entry into or exit out of the palace. Yuwen Shu and Guo Yan [(郭衍)] were put in command. Further, the deputy chief of staff for the Crown Prince's palace, Zhang Heng [(張衡)] entered the Emperor's palace to attend to his medical needs. Zhang expelled all of the ladies in waiting and the eunuchs. Soon thereafter, the Emperor died. Thereafter, there were different views as to how he died. When Consort Chen and the other women of the palace heard of this, they stared at each other in fear and shook with fear. At dusk, the Crown Prince sent a eunuch with a small gold box, personally sealed by the Crown Prince, to be delivered to Consort Chen. When Consort Chen saw it, she, believing that there was poison inside, was very fearful, and did not dare to open it. Only after the eunuch urged her did she open it. Instead, the box contained several tongxin knots [(同心結, a decoration showing love)]. Her ladies in waiting were relieved and became happy, stating to each other, "Finally, death is avoided." Consort Chen, in shame and anger, sat down and refused to accept the box. The ladies in waiting forced her to bow to the eunuch. That night, the Crown Prince ordered Consort Chen to have sexual relations with him.
In April 2013 the tomb of Emperor Yang was discovered in Yangzhou. Two brick-lined tombs were discovered in the Hanjiang District of Yangzhou during work on a housing development. A stone epitaph found in the western tomb was inscribed with the title "Tomb epitaph of the late Emperor Yang of Sui" (隨故煬帝墓誌), indicating that the tomb was that of Emperor Yang. It is thought that the other tomb may be that of the emperor's consort, but it has not been properly excavated yet.
While no allegations were made at the time that Emperor Wen's death was anything other than the result of illness, starting from the time of the succeeding Tang Dynasty, it was generally assumed that Emperor Wen was killed on Emperor Yang's orders—although more neutral historians generally assumed it to be true while stating that there was no direct evidence. An Example is the Song Dynasty Historian Sima Guang's Zizhi Tongjian, generally considered one of the most reliable, albeit secondary, sources in Chinese history, which, after mentioning Emperor Wen's death and giving a commentary on Emperor Wen's reign, then gave this account:
