Princess Changrak (Korean: 창락궁주; 창락공주; Hanja: 昌樂宮主; 昌樂公主; d. 1216[a]) was a Goryeo Royal Princess as the third daughter of King Injong and Queen Gongye who would become the mother of King Gangjong's second wife, Queen Wondeok.
[1] Then, she married her paternal aunt's son–Wang Seong the Marquess Sinan (신안후 왕성)[2] and had two sons: Wang Won the Marquess Gyeseong (계성후 왕원) and Wang Jin the Marquess Yeongin (영인후 왕진) who would become the father of King Huijong's wife, also a daughter who married King Gangjong.
[3] Meanwhile, since came from the same ancestor, the princess was once Wang Seong's paternal fourth cousin.
[4] To honor his deceased maternal grandmother, King Gojong reduced the number of palace's side dishes and ordered his officials to wore mourning clothes for a day.
[2] Meanwhile, Wang Seong died in 1178 (8th years reign of King Myeongjong) and suspended the inquiry for three days.