Queen Wonyong
Queen Wonyong of the Chŏngju Yu clan was a Goryeo royal family member as the granddaughter of King Daejong, son of King Taejo who became the 5th wife of her half first cousin once removed, King Hyeonjong which she then followed her grandmother's clan, the Chŏngju Yu.
Her husband's mother, Grand Queen Mother Hyosuk was initially her paternal aunt, while his first and second wife was initially her first cousin. Yu entered the palace in 1013 as his fifth wife and was posthumously honoured as Queen Wonyong later. They didn't have any children.