Prince Kusakabe (草壁皇子)
Prince Kusakabe (662-May 10, 689) was a son of Emperor Temmu and Princess Uno no Sarara (Empress Jito). His wife was Princess Ahe (later the Empress Genmei), who was a daughter of Emperor Tenchi and a half-sister of Empress Jito. Prince Kusakabe was a father of Empress Gensho, Imperial Princess Kibi (later the wife of Prince Nagaya), and Emperor Mommu. His shigo (a posthumous name) was Okanomiyani amenoshita shiroshimeshishi Sumeramikoto or Okanomiya gyo tenno. He was also called Emperor Okamiya or Emperor Nagaoka.
Prince Kusakabe was born in 662. In 672, at the outbreak of Jinshin War, he accompanied his parents with other brothers including Prince Otsu. On March 23, 673, Emperor Temmu ascended the throne at Asuka Kiyohara no miya Imperial residence.
Prince Kusakabe became the de facto successor at Yoshino Pact in 679, and became the crown prince in February, 681. Since his mother, Empress Uno no Sarara, was a person of position and her older sister had already died, it is considered that he became the crown prince before Prince Otsu.
In August, 686, he and his mother were entrusted with the sovereign right from Emperor Temmu who were seriously ill, after that Emperor Temmu demised in September. Next month, Prince Otsu was executed on charge of rebellion.
However, Empress Uno no Sarara, did not let Prince Kusakabe ascend the throne immediately after the execution of Prince Otsu. It seems that his youth and antipathy toward Prince Otsu's execution at Imperial Court prevented his enthronement.
On May 10, 689, he died without ascending the throne. In 758, after the enthronement of Emperor Junnin, Prince Kusakabe was conferred the title "Okanomiyani amenoshita shiroshimeshishi Sumeramikoto or Okanomiya gyo tenno." The poem which he sent to ISHIKAWA no Uchimyobu is found in "Manyoshu (Collection of Ten Thousand Leaves)." His tomb is the Mayumi no oka Mausoleum, that is located in Takatori-cho, Takaichi-gun, Nara Prefecture.
Prince Kusakabe died at an early age, however, most of his families including his parents, wife, sons, daughters and close relatives took throne (moreover the theory that Prince Nagaya, who was the husband of his second daughter Imperial Princess Kibi was also treated as Imperial Prince as a special case and had the right of succession to the Imperial Throne has been pointed out), while his descendants became bearers of culture and politics as main branch of the Imperial line from the Emperor Tenmu in Nara Period.
However, its male line came to an end in 744, when his great grandchild, Prince Asaka, died at an early age. (There is a theory that he was assassinated by FUJIWARA no Nakamaro.)
When it comes to the maternal side of a family, HIKAMI Kawatsugu (the great-great-grandson of Prince Kusakabe), the son of his great grandchild Imperial Princess Fuwa and Prince Shioyaki (a nephew of Prince Kusakabe) was also banished on a charge of rebellion with his younger brother, HIKAMI no Shikeshimaro (HIKAMI no Kawatsugu's War). Then, after the demise of Emperor Kammu, they were forgiven and returned to Kyoto. However, after he was appointed Izu no kami (Governor of Izu Province) in 812, he was never heard of again.
Imperial Prince Osabe (the great-great-grandson of Prince Kusakabe), who was the son of Imperial Princess Inoe (a daughter of Emperor Temmu), a older sister of Imperial Princess Fuwa, and Shirakabe no okimi (Prince Shirakabe, later Emperor Konin), was formally installed as Crown Prince as the symbol of merger of Tenchi and Temmu Imperial Line at the time of enthronement of his father, with demise of his aunt, Empress Koken Empress Shotoku. However, Imperial Prince Osabe was entrapped by a scheme of FUJIWARA no Yoshitsugu and a FUJIWARA no Momokawa (brothers) from the Ceremonial House of the Fujiwara clan who opposed his investiture of the Crown Prince; and eventually he was demoted to common people for allegedly having put a curse on Emperor Konin, thereafter he and his mother died an unnatural death. Imperial Princess Sakahito, who was an older sister of Imperial Prince Osabe, became a wife of the Emperor Kammu and gave birth to Princess Asahara (Emperor Heizei's wife), however, Princess Asahara was not able to have a child and the maternal side of a family came to an end.
In 844, among the Imperial Families that had undergone demotion from nobility to subject, Prince Mineo (a great-grandchild of Imperial Princess Kibi) was given the surname of "TAKASHINA no Mahito", and became the ancestor of the Takashina clan. However, since Mineo's grandson TAKASHINA no Moronao was an adopted child, his family line came to an end.