Lifespan: Unknown to 7/1 of Tenbun 3 (1534)
Other Names: Hachirō-gorō, Shikibu-no-jō, Shikibu-no-taifu, Mikawa-no-kami, Jurian-jokan (Buddhist name)
Rank: sengoku daimyō
Clan: Mariyatsu-Takeda (members of the Kazusa-Takeda clan)
Father: Mariyatsu Nobukatsu
Siblings: Jokan, Zenhō, sister (wife of Miura Yoshioki)
Children: Zenkan (Takeda Taifu), Nobutaka, Nobumasa
Mariyatsu Jokan served as a sengoku daimyō of Kazusa Province during the Sengoku period.
Origins of name
In numerous accounts from the period, he is referred to under his posthumous Buddhist name of Jurian-Jokan. In genealogical records, his real name appears as Nobuyasu or Nobukiyo. Although there is no basis for his real name in authenticated sources, Jokan has traditionally been referred to as Nobuyasu.
Signatures have been discovered of an individual who was the apparent head of the Mariyatsu-Takeda family in Jokan’s era under the name of Shikibu-no-jō Nobukiyo. Based on this evidence, it is surmised that Jokan’s real name was Nobukiyo, but an individual of the same name was the builder of Odaki Castle (Ōtaki Castle). In the genealogy of the descendants of the founder of the Odaki-Takeda clan, there is a branch for his son, Mariyatsu Naonobu, and a separate branch for his grandson, Mariyatsu Tomonobu. The representation in this genealogy of a close relationship between the Ōtaki-Takeda and the Mariyatsu-Takeda may, however, be erroneous information. Meanwhile, the individual identified as Nobuyasu in the Mariyatsu genealogy may have been the head of the Mariyatsu-Takeda clan or a proxy for the head of the clan and may have been an illegitimate son or younger brother (Nobuaki) of Jokan’s father, Nobukatsu, and separately known under the name of Mariyatsu Zenhō.
In any event, in the course of further research and theories, the real name of Jokan currently remains uncertain.
In Kazusa, Jokan competed for power against the Chiba and Hara clans. In 1516, he received reinforcements from Ise Moritoki (Hōjō Sōun) of Sagami Province to fight against the Hara clan. In 1518, in a bid to expand the authority of the Mariyatsu-Takeda family, Jokan joined forces with Ashikaga Yoshiaki (the Oyumi kubō) who opposed Ashikaga Takamoto (the Koga kubō and son of Ashikaga Masauji). As a result, the Mariyatsu-Takeda family acquired greater influence than the Osanami-Takeda family of the main branch in the camp of the Koga kubō.
As the conflict over Musashi Province intensified between the Gohōjō and the Ōgigayatsu-Uesugi family, upon an appeal from the Ōgigayatsu-Uesugi, Jokan confronted Hōjō Ujitsuna and, in 1524, brought Shinagawa Harbor into his sphere of influence. Further, he allied with Satomi Yoshitoyo of Awa, gaining an advantage in his conflict with the Gohōjō, expanded his territory to Musashi, and brought Kamakura under his control.
Until 1525, records indicate that Jokan was serving in the priesthood and there is evidence that he transferred the headship of the clan to his lineal heir, an individual named Takeda Taifu. There is a likelihood that Takeda Taifu corresponds to an individual in the family genealogy referred to as Mariyatsu Zenkan.
Later, Ashikaga Yoshiaki approached Jokan in regard to a reconciliation with Hōjō Ujitsuna, but Jokan rejected him. During the succession struggle in the Satomi clan known as the Inamura Incident (Tenbun Discord), Jokan supported Satomi Yoshitoyo, but some members of the family backed Satomi Yoshitaka (from an illegitimate branch of the Satomi). After Jokan’s death, this division of support for opposing members of the Satomi served as an underlying cause for ruptures in the Mariyatsu family.
Jokan died in 1534. It appears that his lineal heir, Takeda Taifu (Mariyatsu Zenkan) died around this same time.