Main •
Joo Sang-wook as
Yi Bang-won, King Taejong, the 3rd King of Joseon. •
Park Jin-hee as
Queen Wongyeong, the 3rd Queen Consort of Joseon. •
Ye Ji-won as
Queen Sindeok, the 1st Queen Consort of Joseon. • Kim Myung-soo as
Yi Bang-gwa, King Jeongjong, the 2nd King of Joseon. "Prince Yeong-an" (). "Grand Prince Ik-ahn" (). • Jo Soon-chang as Yi Bang-gan, "Grand Prince Hoi-an" (). • Choi Da-hye as Princess Gyeongsun, Yi Seong-gye and Queen Sindeok's daughter. • Lee Ha-eun as Lady Ryu Hyun-bin :As Bang-seok's wife, she later causes an adultery case with the eunuch Yi Man. • Han Yoon-ji as Princess Gyeongnyeong, wife of Yi Bang-beon.
Yi Bang-won's family •
Kim Min-gi as
Yi Do, Prince Chungnyeong. • Gu Hyun as 5-year-old Yi Do • Joo An as 1-year-old Yi Do • Kim Ro-woon as baby Yi Do •
Lee Tae-ri as
Yi Je, Prince Yangnyeong. • Kim Joon-ui as 8-year-old Yi Je • Kim In-woo as 4-year-old Yi Je • Jung Shi-hoon as
Yi Bo, Prince Hyoryeong. • Shin Seo-woo as 7-year-old Yi Bo • Im Ye-jin as young Princess Jeongsun, Yi Bang-won and Queen Wongyeong's 1st daughter. • Lee Do-yeon as Princess Gyeongjeong, Yi Bang-won and Queen Wongyeong's 2nd daughter. • Park Soo-eon as young Princess Gyeongjeong • Lee Ye-seo as Princess Gyeongan, Yi Bang-won and Queen Wongyeong's 3rd daughter. • Kim Vi-ju as
Queen Soheon.
Yi Seong-gye's family •
Ye Soo-jung as
Queen Sinui, Yi Seong-gye's first wife and Yi Bang-gwa & Yi Bang-won's mother.
Queen Wongyeong's family •
Kim Kyu-chul as Min Je, Queen Wongyeong's father. • Lee Eung-kyung as Lady Song of the Yeosan Song clan, Queen Wongyeong's mother. • Kim Tae-han as Min Mu-gu, Queen Wongyeong's first younger brother. • Noh Sang-bo as Min Mu-jil, Queen Wongyeong's second younger brother.
Yi Bang-won's political comrades • Park Yoo-seung as Yoon So-jong, a politician in the early Joseon dynasty and at the end of the Goryeo dynasty. • Nam Sung-jin as
Ha Ryun. • Kim Bup-rae as Jo Young-mu, one of Joseon's founding helper and the public relations. • Kim Geon as Jo Young-gyu, Yi Bang-won's person who helps him in the Seonjuk Bridge's accident. • Noh Young-guk as Jo Jun, a
Chwaŭijŏng and one of Joseon's founding helper. • Kim Young-gi as Kwon Geun, a politician in the early Joseon dynasty and the end of the Goryeo dynasty. • Park Chil-yong as Nam Jae •
Jung Tae-woo as Yi Suk-beon • Lee Hyun-kyun as Park Eun •
Kang Ji-sub as
Hwang Hui • Cha Ki-hwan as Yi Geo-yi •
Im Ho as Yu Jeong-hyeon
Yi Seong-gye's political comrades •
First strife of crown prince • Lee Kwang-gi as
Jeong Do-jeon, one of Joseon's founding helper. • Lee Ki-yeol as Nam Eun • Lee Kyung-young as Sim Hyo-saeng • Lee Woo-seok as Park Wi • Second strife of crown prince • Ahn Hong-jin as • Park Jang-ho as Yi Maeng-jong, Prince Uiryeong. • Jo Sa-eui's rebellion • Jung Eui-gap as Jo Sa-eui
Goryeo people •
Choi Jong-hwan as
Jeong Mong-joo, the last loyalist of Goryeo. •
Im Ji-kyu as
King Woo, the 32nd King of Goryeo. • Song Yong-tae as
Choi Young. • Nam Myung-ryul as
Yi Saek :Both of Jeong Do-jeon, Jeong Mong-ju, Ha-Ryun, Yoon So-jong, Yi Soong-in's teacher and a spiritual leader in the Shinjin Grand Temple, also the later Goryeo's warrior. • Im Byung-gi as Byun An-ryeol • Park Sang-jo as Jo Min-soo, a warrior in the later Goryeo who cause a revolt with Yi Seong-gye. • Ki Eun-yoo as
King Chang, the 33rd King of Goryeo. • Park Hyung-joon as
Wang Yo, King Gongyang, the last King of Goryeo. • Kim Jin-gook as Jeong Mong-ju-related minister
Others • Park Yeo-reum as an old nanny • Choi Shi-in as
gisaeng • Lee Choon-sik as Noh Hee-bong, Taejo and Taejong's eunuch. • Jin Zheng-gang as
Zhu Yuan-zhang • Kim Do-won as young Bul-no, a child born to Yi Bang-gwa and his concubine. == Production ==