Emperor Wen of Sui dies in 604; his twenty-four-year-old son succeeds him as Yang Guang or Sui Yang Di (Yang Kuang, or Sui Yang Ti).

Under the lustful and extravagant Yang, the strong fiscal base built by Emperor Wen quickly evaporates, resulting in widespread revolts.

An immediate challenge that Emperor Yang faces us a rebellion by his brother Yang Liang, the commandant at Bing Province, who is encouraged by the generals Wang Kui and Xiao Mohe.

Yang Liang receives support from nineteen provinces, but lacks a coherent plan as to whether to try to challenge Emperor Yang for the control of the entire empire, or just the region north of the Yellow River.

After some initial successes, Yang Liang's offenses stall.

Emperor Yang sends Yang Su against him, and Yang Su proceeds quickly to Yang Liang's headquarters at Bing Province, capturing Xiao and forcing Yang Liang to surrender.

Emperor Yang does not execute Yang Liang, but reduces him to commoner rank and imprisons him for the rest of his life.

Believing in the words of the sorcerer Zhangchou Taiy that the geography of Chang'an is not conducive to his health, …

…Emperor Yang goes to Luoyang in winter 604, designating it as the eastern capital, and will rarely return to Chang'an hereafter, although Chang'an remains officially the main capital.

He orders that major construction projects be carried out at Luoyang, commensurate with the necessities of having it as the second capital, leaving his oldest son, Yang Zhao the Prince of Jin, in charge of Chang'an.

He conscripts several hundred thousands of young men to dig a lengthy trench to surround the Luoyang region, intending that it serve as a defense perimeter.

He also orders that women and servants be exempted from head taxes, and that men will only be considered adults (i.e., subject to conscription) when they turn twenty-one.

Emperor Yang creates his wife Crown Princess Xiao empress, and Yang Zhao crown prince, in spring 605.

He also abolishes the offices of military commandants.

He, at this time, trusts Empress Xiao's brother Xiao Cong the Duke of Ju (Western Liang's last emperor) and makes him, as well as many of her other relatives, important officials, creating for him the greater title of Duke of Liang.

Starting in 605, Emperor Yang also begins a massive number of construction projects—including the building of the imperial palace at Luoyang, described to be particularly luxurious.

Further, he conscripts a large number of men to build the Tongji Canal, connecting Luoyang with the Yellow River and connecting the Yellow River with the Huai River, as well as to rebuild the Han Canal, connecting the Huai River and the Yangtze River.

The two canals, which will eventually become parts of the Grand Canal of China, are said to be constructed within five months, but at substantial cost of life—forty to fifty percent of the men employed.

Emperor Yang also orders that some forty secondary palaces be built around the empire, so that he can visit the various provinces, arguing that he needs to do so to see the conditions of the empire so that he can govern effectively.

Yang Zhao the Crown Prince becomes ill while visiting Luoyang in summer 606, and soon dies.

Emperor Yang will not create another crown prince for the rest of his reign, creating Yang Zhao's sons Yang Tan, Yang Tong, and Yang You imperial princes, while initially apparently tacitly considering his second son, Yang Jian the Prince of Qi, the de facto successor, leaving Yang Jian in charge of Luoyang whenever he is away from Luoyang.

Yang Su, whom Emperor Yang pretends to respect but actually fears, dies in summer 606.

Also in 606, Emperor Yang orders that two massive food storage facilities—the Luokou Storage and the Huiluo Storage—be constructed near Luoyang.