Deok Man (Lee Yo Won) was born a twin but was sent to a place far away by her father, King Jin Pyung (Jo Min Ki) in order to protect her from the royal court lady, Mishil (Uee / Ko Hyun Jung) who tries to snatch away the throne from the royal successor. Deok Man was later brought back to the Silla palace, where she joined forces with her twin sister Princess Chun Myung (Park Ye Jin) to oppose Mishil. However, Mishil devised sinister plans to have the two Silla princesses exiled from the kingdom, and in a secretive battle, Princess Chun Myung was accidentally killed. But Princess Deok Man shrewdly enlisted the help of General Kim Yu Shin (Uhm Tae Woong) and eliminated her archenemy Mishil. She then became Queen Seon Deok, the first female ruler of the Silla kingdom. This drama is about a story of a beautiful queen, who has to give up her love to save the people and thus, leaving behind many brilliant achievements.