Qin Wang Li Shimin (played by Tang Guoqiang) ascended to the highest ruling position in the Tang Dynasty in the ninth year of Wude. After ascending the throne, he worked hard to govern the country and commanded the Tang army to conquer the Jie Li tribe, which had dominated the north for many years, and achieved the unification of the country. Afterwards, the far-sighted Emperor Taizong of Tang was determined to make the country, which had been in war for many years, take the path of peaceful development. He urged the unity of all ethnic groups and relocated hundreds of thousands of Jie Li tribe victims who were in famine to the inland areas and distributed them to good fields. His broad mind was deeply loved by people of all ethnic groups. However, the open and secret struggles among several sons for the throne also made him feel uneasy. Among them, the struggle for power between the illegitimate princes Li Ke (played by Nie Yuan) and Li You (played by Wen Hao) and the three legitimate princes was particularly thrilling. The marriage turmoil between Emperor Taizong of Tang and a woman named Zheng, and the heart-wrenching love story between Princess Ankang (played by Zhang Lanlan) and two outstanding men, fully reflect the ups and downs of the history of the prosperous Tang Dynasty...