Kim Jung-hyun (King Cheoljong) and Cha Cheong-hwa (Court Lady Choi) were also in Crash Landing on You (2019).
The series is based on the Chinese novel Go Princess Go and its web series adaptation Tai zi fei sheng zhi ji (2015) which aired on LeTV.
This is the second drama in which Seol In Ah (Jo Hwa Jin) and Kim Jung Hyun (King Cheoljong) appear together after School 2017.