Officai history confirmed that there are many Hi in ancient times, certain ones were Imperial Princess Sakahito (Imperial Princess of Emperor Konin, younger maternal half-sister of Emperor Kanmu), Emperor Kanmu's empress, Princess Asahara, Emperor Heizei's empress and Imperial Princess Oyake (both Imperial Princesses of Emperor Kanmu, younger maternal half-sister of Emperor Heizei), Princess Takatsu (Imperial Princess of Emperor Kanmu, younger maternal half-sister of Emperor Heizei) and TAJIHI no Takako (daughter of TAJIHI no ujinokami, upgraded from Fujin [consort of emperor]), both of them were Emperor Saga's empress, Imperial Princess Ishi (Imperial Princess of Emperor Koko, aunt of Emperor Daigo), Emperor Daigo's Empress, and as wife of prince (crown princess in modern time), Princess Ahe (Imperial Princess of Emperor Tenchi, aunto of Prince Kusakabe, but Prince didn't ascended the throne because he died), Prince Kusakabe's wife, and Imperial Princess Koshi (Imperial Princess of Emperor Kanmu, younger maternal half-sister of Imperial Prince Otomo, but the princess died before the prince ascended the crown prince and the throne), Imperial Prince Otomo's wife.
古代の妃に関して、正史などによって確実なのは桓武天皇妃酒人内親王（光仁天皇皇女・桓武天皇異母妹）、平城天皇妃朝原内親王及び大宅内親王（ともに桓武天皇皇女・平城天皇異母妹）、嵯峨天皇妃高津内親王（桓武天皇皇女・嵯峨天皇異母妹）、同多治比高子（多治比氏守娘・夫人からの昇格）、醍醐天皇妃為子内親王（光孝天皇皇女・醍醐天皇叔母）であり、他に皇太妃（現在の皇太子妃）として草壁皇子妃阿閇皇女（天智天皇皇女・草壁皇子叔母、ただし皇子は即位せずに死去）、その他の例として大伴親王妃高志内親王（桓武天皇皇女・大伴親王異母妹、ただし妃は親王の立太子・即位前に死去）の例が存在する。