Yang Di was the second emperor of the Sui Dynasty, and his second son was his mother. 5 1 year, he became the king of Jin. In 589, he served as a marching marshal; In 600, he became a prince. He became emperor in 64, with a great title, and was in office for 14 years. Emperor Yang Di recorded in Biography of Sui Shu's sai-jo:? Beauty posture is better than Huimin. ? Some people compare Shang Zhouwang and Qin Shihuang with him and call them tyrants. After he acceded to the throne, he had great ambitions for the national certificate and worked hard to realize it. During his reign, he built the Grand Canal, Daxing City, Luoyang City and Dongdu, opened up the territory to smooth the Silk Road, started the imperial examination, and levied three taxes on Koguryo. The Grand Canal and the Imperial Examination have influenced future generations for thousands of years.

Yang Guang's mother is the wife of Emperor Wendi Dugu, while Li Yuan's mother is Dugu. They are sisters. Therefore, Yang Guang and Tang gaozu are very close brothers. Yang Guang was not made a prince at first, but was destroyed by his brother Yang Yong when he was in office, so he made many friends and relatives. At this time, Yang Guang chose to make friends with Tang gaozu, who is also a smooth person. As a courtier, he also needed a big tree to rely on, and this person was Yang Guang, so their relationship was very close at first.

Yang guang and Li yuan, because of the hostility of power Because Li Yuan was a loyal minister of the Sui Dynasty, he has always been loyal to Emperor Wendi and the rule of Emperor Wendi. The continuation of ancient imperial power was the eldest son inheritance system. So one hundred years later, the throne of Emperor Wendi of Sui Dynasty will be passed on to Prince Yong Yang. However, Prince Yong Yang was weak and Yang Guang was brave, so Yang Guang coveted the throne. As a loyal minister of the Sui Dynasty, Li Yuan naturally wanted to protect the imperial power, so Yang Guang and Li Yuan became enemies. Before becoming a crown prince, Yang Guang always pretended to be very simple in front of his parents in order to please them. He also sent rare treasures such as golden snakes and camels to flatter his concubine, Mrs. Xuanhua. Therefore, Mrs Xuanhua often denigrates Yong Yang. In the 20th year of Emperor Chengzu of Ming Dynasty, Emperor Wendi abolished Prince Yong Yang and established Yang Guangguan in November? Prince.

In the second year of Renshou (602), Queen Dugu died. Two years later, Renshou, four years in July, Emperor Wendi was seriously ill and died in Yu Dabao Hall. Yang Guang ascended the throne and was called Emperor Yang Di after he ascended the throne. He exposed his extravagance, decadence and cruelty. As we all know, it was a waste of money and human resources to build the Grand Canal during the reign of Yang Guang. He levied food from the people to enrich the state treasury, and the people were even more miserable. Complaints also reached the court, and Yang Guang and Yang Di were ultimately unpopular. Wendi and Sui Wendi cultivated Li Yuan from childhood, and Li Yuan lived with his uncle since childhood. Tang gaozu always remembered that Yang Guang persecuted his uncle in order to seize the throne. He has never forgotten Emperor Wendi's concern for him, so he has been looking for opportunities to fight for things that belong to Emperor Wendi and the world.