Zhao Liying as Lu Zhen:
The daughter of a wealthy merchant by a concubine. After her father's death, she was driven out by her stepmother and eventually fled into the palace to hide from the assassination attempts. She slowly climbs up the palace hierarchy to become the first female prime minister of her nation.
Chen Xiao as Gao Zhan:
9th Prince Changguang of Northern Qi and later becomes Emperor Wucheng after his older half-brother's death. His mother was the second Empress Yujiulǘ. He holds a strong grudge against Empress Lou whom he sees as the main culprit behind his mother's death. His childhood sweetheart, Xiao Guanyin, breaks his heart when she marries his older brother. He returns to the palace and he gradually recovers from his heartbreak when he meets Lu Zhen...They become extremely devoted to each other. Due to their extreme difference in social status, his sister's disapproval, and many other political reasons, Gao Dan cannot take Lu Zhen as his wife nor bestow her any formal marital titles.
Yang Rong as Xiao Guanyin:
Lu Zhen's arch love nemesis. She and Gao Zhan were childhood sweethearts and deeply love with each other until she abandoned Gao Zhan and married his older brother, Gao Yin.
Emperor of Northern Qi and biological son of Empress Dowager Lou. Kind-hearted, he succeeds the throne when another brother died. Genuinely loves Xiao Guanyin, but she only has eyes for Gao Zhan.
Tang Yixi as Shen Bi:
A female official who is a jealous rival of Lu Zhen in the palace. She is also infatuated with Prince Gao Zhan and plots to rid of Lu Zhen.
Wu Yinghao as He Danniang:
A good friend of Lu Zhen who loves to eat.
A niece of Empress Dowager Lou. She is vested in protecting the interest of her clan and she also covets for more personal power.
Liu Xuehua as Empress Dowager Lou:
A vicious, ruthless woman who would stop at nothing to protect her son's throne.
Jiang Hong as Wang Xuan:
Lady-in-waiting to Xiao Guanyin. She is staunchly loyal to her master. Though her strict and serious nature commands respect, she still has a soft heart. She does not trust blindly and has a sense of justice.
Li Yixiao as Gao Xiang:
Eldest Princess. Sister of Gao Zhan. She objects to her brother's love for Lu Zhen and does not approve of their union. She and Empress Dowager Lou get embroiled in a bitter political rivalry.
Son of a prominent official and older brother to Shen Jiamin. Also a military officer of the Northern Qi who quietly protects Lu Zhen. He harbors romantic feelings for Lu Zhen in silence and comes to her assistance whenever she's in trouble.
Diao Xue as Shen Jiamin:
A female official. Daughter of a prominent official. Though a kindhearted girl at heart, she grew up privileged and spoiled by her older brother. Hoping to politically elevate her clan through royal marriage, she vies for Gao Zhan's affection and sees Lu Zhen as a threat.
Gao Yunxiang as Xu Xianxiu:
Brother-in-law of Gao Zhan and husband of the Eldest Princess, Gao Xiang
Wang Lin as Madam Zhao:
Wife of Lu Jia and stepmother to Lu Zhen. She tries to silence Lu Zhen, which forces her to flee to the palace.
Medina as Beautiful Lady Du:
A princess from a foreign land
Lu Jiarong as Lady Yueguo:
Niece of Madam Zhao.
After a childhood drowning incident, she became mentally retarded and only retained the memory of an 8 year old. She barely knows what marriage means, but enters into a political marriage with Gao Zhan.