The Jowa Incident (承和の変)
The Jowa Incident is believed to be the first incident to expulse other clans from the Imperial Court plotted by the Fujiwara clan in the early Heian period.
The Emperor Saga abdicated in 823, and in turn the Emperor Junna, the Emperor Saga's younger brother ascended the throne. After the Emperor Junna abdicated, the Emperor Ninmyo, a son of the Retired Emperor Saga, inherited the throne in 833. A prince of the Emperor Junna, the Imperial Prince Tsunesada (his mother was the Imperial Princess Masako, a princess of the Emperor Saga) became the Togu (the Crown Prince) of the Emperor Ninmyo. Under the great patriarchal authority-styled command executed by the Retired Emperor Saga, politics enjoyed steadiness for nearly 30 years without dispute concerning the Imperial succession.
Meanwhile, FUJIWARA no Yoshifusa belonging to the Northern House of the Fujiwara clan began to gain power rapidly by winning the confidence of the Retired Emperor Saga and the Empress Dowager TACHIBANA no Kachiko (Empress Dowager Danrin). FUJIWARA no Junshi, a younger sister of Yoshifusa, became the Chugu (the Empress) of the Emperor Ninmyo and bore the Emperor Montoku. Yoshifusa desired that the Imperial Prince Michiyasu (Emperor Montoku) would inherit the throne. With anxiety over the movement to support the Imperial Prince Michiyasu in attaining the position of the crown prince, the Imperial Prince Tsunesada and his father, the Retired Emperor Junna repeatedly petitioned the Retired Emperor Saga for resignation from the position of the crown prince. However, they were persuaded to stay in the position every time.
The Retired Emperor Junna died in 840. The Retired Emperor Saga was also struck down by a serious illness in August 842, two years after the Retired Emperor Junna's death. TOMO no Kowamine, the Togu-bo Tachihaki no Toneri (guard of the crown prince's Quarters), and his friend TACHIBANA no Hayanari, the Tajima no kuni Kokushi (the governor of Tajima Province), both of whom were serving the crown prince, perceived the critical atmosphere due to the retired emperor's illness. Judging that danger was approaching the crown prince, they schemed to transfer him to Togoku (the eastern part of Japan, particularly the Kanto region), and then consulted with the Imperial Prince Abo (a prince of the Emperor Heizei) about the scheme. Without taking their sides, the Imperial Prince Abo reported to the Empress Dowager Danrin, a cousin of Hayanari, about their scheme by sending a secret letter. The Empress Dowager Danrin, who was surprised at the gravity of the situation, consulted the Chunagon (vice-councilor of state) Yoshifusa.
The retired Emperor Saga died on August 28, 842. The Emperor Ninmyo arrested TOMO no Kowamine, TACHIBANA no Hayanari and the alleged conspirators on August 30, two days after the retired emperor's death, directing the Rokuefu (six divisions assuming the guard duty of palace) to strengthen the security of Heian-kyo (the ancient capital of Japan in current Kyoto). The crown prince tendered a resignation immediately to the emperor, but the emperor initially persuaded him to stay in his post by saying that the fault did not lie with the crown prince. However, the political situation changed dramatically on September 5. FUJIWARA no Yoshimi, belonging to the Konoefu (the Headquarters of the Inner Palace Guards), and troops of Konoefu led by Yoshimi besieged the zasho (a room for a noble person) of the crown prince. The Dainagon (chief councilor of state) FUJIWARA no Chikanari, the Chunagon FUJIWARA no Yoshino, and Sangi (councilor) FUNYA no Akitsu were captured when they were working at the office. The Emperor Ninmyo issued the imperial edict and concluded that TOMO no Kowamine and TACHIBANA no Hayanari were rebels. Furthermore, although saying that the Crown Prince Tsunesada had nothing to do with the incident, the emperor fired the crown prince so as to put the responsibility on him. FUJIWARA no Chikanari was expelled from the capital, FUJIWARA no Yoshino was demoted to the Dazai gon no sochi (Provisional Governor-General of the Dazai-fu [local government office in Kyushu region]), and FUNYA no Akitsu was demoted to the Izumo no kuni ingai no kami (a director in Izumo Province other than those stipulated in the law). TOMO no Kowamine was exiled to Oki Province (later, he was relegated to Izumo Province), while TACHIBANA no Hayanari was exiled to Izu Province (on the way to Izu Province, he died at Hozuki, Totomi Province). Moreover, a lot of government officers of Togu-shiki (the Board of the Crown Prince's Affairs) and Togu-bo (Crown Prince's Quarters) serving the crown prince were punished.
After the incident, FUJIWARA no Yoshifusa was promoted to the Dainagon, and the Imperial Prince Michiyasu became the crown prince (later, the Emperor Montoku).
It is a common view that the Jowa Incident was the first incident to expulse other clans from the Imperial Court plotted by the Fujiwara clan. It is believed that FUJIWARA no Yoshifusa realized his wishes of not only letting the Imperial Prince Michiyasu ascend the post of crown prince, but also giving a blow to the influential clans, the Tomo clan (or the Otomo clan) and the Tachibana clan. It is also said that FUJIWARA no Yoshifusa drove FUJIWARA no Chikanari and FUJIWARA no Yoshino to fall, both of whom were Yoshifusa's rivals within the Fujiwara clan. However, setting apart the two personnel in the Fujiwara clan, TOMO no Kowamine was only a branch of the Tomo clan, just as TACHIBANA no Hayanari was of the Tachibana clan. Furthermore, considering Yoshifusa's post as Chunagon at the time; the sixth highest rank in the Daijokan (Grand Council of State), it is impossible for him to cause such an incident alone (notably, Yoshifusa expulsed two senior people) by taking a leading role, even if he was famous as an able person. In addition, according to "Nihon Sandai Jitsuroku" (Veritable Records of Three Reigns of Japan), the Imperial Princess Masako (the Empress of the Emperor Junna), a real mother of the Imperial Prince Tsunesada as well as a real daughter of TACHIBANA no Kachiko, had a furious grudge against her mother after this incident. These matters support the theory that this incident was triggered by a scheme plotted by the Emperor Ninmyo or TACHIBANA no Kachiko to expel the then crown prince. This theory is also supported by the fact that some suspicions were thrown on the crown princes whenever they were expelled after the Nara period. Furthermore, the emperor's stay from May, 842 within a lot of Reizei-in Palace, where the Imperial Prince Tsunesada was living at that time, by reason of the Imperial Palace's repair also supports the theory, because troops serving the emperor that had been staying in the residence on the pretext of the emperor's guard were ready to besiege the crown prince.
Then, after building up promotions, Yoshifusa finally achieved the position of the Sessho and Daijo-daijin (regent and grand minister of state) to become the first subject to be officially appointed to the post, laying the foundation of the Fujiwara clan's prosperity.