San-saemon Incident (三左衛門事件)
The San-saemon incident was the incident in which former retainers of the deceased father and son, Yoshiyasu ICHIJO and Takayoshi ICHIJO, were arrested for attempting to attack Michichika TSUCHIMIKADO, Gon Dainagon (provisional major counselor). The incident occurred in the month following the death of MINAMOTO no Yoritomo, and shook the Kamakura bakufu (Japanese feudal government headed by shogun). The term "San-saemon" originated due to the fact that all of the three (san in Japanese) leaders of the attempt held the position of Saemon no jo (third-ranked officer of the Left Division of Outer Palace Guards).
On February 23, 1199, word reached Kyoto that MINAMOTO no Yoritomo, the first Seii taishogun (literally, "great general who subdued the barbarians") of the Kamakura bakufu, died suddenly on February 16. Michichika TSUCHIMIKADO, who had supported Insei (the government by the retired emperor) as In no betto (chief administrator of the retired Emperor's office) to Gotoba-in (the Retired Emperor Gotoba), had been in confrontation with Yoritomo and Kanezane KUJO, Yoritomo's close associate, for many years. Upon getting this news, he immediately assumed the post of Ukonoe no daisho (Major Captain of the Right Division of Inner Palace Guards), and successfully recommended MINAMOTO no Yoriie, Yoritomo's successor, to the Sakone no chujo (Middle Captain of the Left Division of Inner Palace Guards) post that had been vacated.
However, on March 12, the same year, Masatsune NAKAHARA, Motokiyo GOTO, and Yoshinari ONO, all of whom were retainers of the Ichijo family (in the lineage of the Nakamikado family), were suddenly arrested for attempting to attack and kill Michichika TSUCHIMIKADO. The Ichijo family were relatives of MINAMOTO no Yoritomo: Yoshiyasu ICHIJO, who died two years before, was the husband of Yoritomo's younger sister and Takayoshi, Yoshiyasu's son who died suddenly the following year (or five months before the arrest) was a nephew of Yoritomo. Each of them played a distinguished role as Shugo (a constable) in Kyoto, and the three persons were not only retainers of the Ichijo family but gokenin (immediate retainers of the shogun) in Kyoto. In other words, assisting the jobs of the father and son of the Ichijo family, the trio were those that could be said to be representatives of the Kamakura bakufu in Kyoto.
Therefore, the suspicion was raised that the Kamakura bakufu might have attempted to kill Michichika. During this situation, the leaders of the Kamakura bakufu, including Yoriie, felt a sense of crisis, and sent Chikayoshi NAKAHARA, the government commissioner, to Kyoto to explain the situation. As the result, the Imperial court accepted the explanation. However, the San-saemon officers (Nakahara, Goto, Ono) had their territories confiscated and were made to return to Kamakura, and Motokiyo GOTO was also dismissed from the Sanuki no kuni no kami (Provincial Governor of Sanuki) post that he had also assumed. The trio (court nobles and government officers) of Kintsune SAIONJI (Yoshiyasu's son-in-law), Yasuie JIMYOIN (Yoshiyasu's cousin and adopted son) and MINAMOTO no Takayasu, all of whom had a close relationship with the Ichijo family, were prohibited from entering the Imperial court and lost their power. In addition, priest Mongaku who was intimate with the Ichijo family as well as the Kamakura bakufu was exiled to Sado Province. Consequently, the Kamakura bakufu faction in the Imperial court was temporarily fatally damaged.
It is thought that Michichika TSUCHIMIKADO was somewhere in the background of this incident. However, "Gukansho" (Jottings of a Fool), written by Jien, a young brother of Kanezane KUJO includes the descriptions that the incident occurred while Kagesue KAJIWARA, a powerful gokenin (retainer of the shogun) close to MINAMOTO no Yoriie was staying in Kyoto and that OE no Hiromoto, Mandokoro betto (Director of the Administrative Board) in the Kamakura bakufu was an associate of Michichika. Concerning this matter, Shosuke KOUCHI points out as follows: The article on February 20 and 21, 1198, in "Gyokuyo," a diary written by Kanezane KUJO, describes that MINAMOTO no Yoritomo had the intention of recommending Imperial Prince Morisada, an elder brother of the Emperor and a distant relative of Yoritomo, as the successor to Emperor Gotoba (at that time) after the Emperor abdicated. Ignoring this, Emperor Gotoba made Imperial Prince Tamehito (later Emperor Tsuchimikado), his biological child, the Crown Prince on the eleventh of the same month and abdicated the throne in favor of Tamehito on the same day. However, if Yoritomo's proposal was true, it is supposed that not only Michichika TSUCHIMIKADO, the maternal grandfather of Imperial Prince Tamehito, but also Gotoba-in (the Retired Emperor Gotoba), who would lose the power to control the nation if Morisada became Emperor, opposed it strongly: it is also thought that relations between the Imperial court and the bakufu were seriously strained at this time. Based on Kouchi's theory, the situation was as follows: taking advantage of the death of Yoritomo, Hiromoto and Kagesue tried to shift the responsibility of having considered making Morisada Emperor onto the Ichijo family and the Jimyoji family, as a means of getting the situation under control and to rebuild relationships between Yoriie, the new shogun, and Gotoba-in.
Two months after Michichika TSUCHIMIKADO died in 1202, Yoshitsune KUJO, son of Yoshitsune KUJO, was appointed to the Sessho (regent) post. Taking this opportunity, the three kugyo (court nobles) or government officers, who were relatives of the Kujo family, returned to the national political world. Nobuyoshi ICHIJO (Yoshiyasu's son), the head of the Ichijo family, and his nephew, Yoriuji ICHIJO (Takayoshi's son), were also employed as trusted personnel of Gotoba-in: the San-saemon trio were pardoned as well, but Mongaku alone, who was disliked by Gotoba-in, died in exile. Gotoba-in still had complaints against the Kamakura bakufu. However, as Gotoba-in's government structure came to be formed (based on the support of the Kujo family, the Saionji family, and the Ichijo family in the lineage of the Nakamikado family), and as MINAMOTO no Sanetomo, who was considered to belong to the Imperial court faction, assumed the shogun post, the Imperial court lost reasons to confront the Kamakura bakufu. Relationships between the Imperial court and the Kamakura bakufu remained stable until MINAMOTO no Sanetomo was assassinated.
TAIRA no Rokudai (a son of TAIRA no Koremori), who escaped death due to Mongaku's guarantee when the incident was exposed, was killed together with Mongaku. As repercussions for this incident, the direct descendant family of the Taira clan, which had nothing to do with the incident, ended up breaking off.