The Promise of Chang'an

Synopsis:
The story is set in the fictive Sheng country. He Lan Ming Yu is an honest and bright young lady. In her young years, she gets to know the 9th Prince Xiao Cheng Xu by chance. The two get along well and gradually develop feelings for each other. However, fate turns against them and while fake news that Cheng Xu died on the battlefield spread, Ming Yu is forced to marry Cheng Xu’s third older brother and reigning king Xiao Cheng Rui . Cheng Xu helps Cheng Rui establish a great and stable country through continuous big achievements on the battlefield, but Cheng Rui is filled with jealousy
towards his outstanding younger brother. When the truth about the death of Cheng Xu’s mother comes to light, Cheng Xu is determined to usurp the throne to take revenge. But before Cheng Xu succeeds, Cheng Rui dies from an old illness after
ordering his son Xiao Qi Yuan to succeed the throne. Cheng Xu is forced to assist Qi Yuan while he grows up, and tries to revive his relationship with Ming Yu at the same time. Qi Yuan, however, is dissatisfied with Cheng Xu controlling him.
When he finds out that his uncle has an affair with his mother, his hate towards Cheng Xu grows immensely. Ming Yu tries her best to reconcile her son with Cheng Xu.