Princess Heungbang was a Goryeo Royal Princess as the youngest daughter[1] of King Taejo and Queen Sinmyeong. She was also the younger sister-in-law of King Gyeongsun of Silla, who later married her half brother, Prince Wonjang.[1] Princess Heungbang had a son Prince Heungbang and a daughter Lady Daemyeong, who would become King Gyeongjong's fifth wife.[2][3][4] From her title, Heungbang became the first Korean Princess who held the title Gung-ju (궁주; 宮主). The use of the title Gung-ju for the king's daughter began with the case of Princess Heungbang. In addition, the title Gung-ju was also used for princesses, and this form continued throughout the Goryeo periods.[5][6]