Awa-Katsuyama Domain

Most of the Bōsō Peninsula was controlled by the powerful Satomi clan during the Sengoku period. The Satomi fought numerous battles with the Later Hōjō clan of Odawara for control of the Kantō region. In 1580, Satomi Yoriyoshi built Tateyama Castle in southern Awa Province to guard the southern portion of his territories and increase his control over the entrance to Edo Bay. The castle is rebuilt by his son, Satomi Yoshiyasu in 1588, who also built a fortified residence, or jinya at Katsuyama, and what is now part of the city of Kamogawa to protect the northeastern approaches to Tateyama Castle. Following the Battle of Odawara in 1590, the Kantō region was assigned to Tokugawa Ieyasu, who confirmed the Satomi as daimyō of Awa and Kazusa Provinces, with revenues of 92,000 koku. Following the Battle of Sekigahara, Satomi Yoshiyasu also gained control of Kashima District in Hitachi Province, which increased his holdings to 122,000 koku. After his death in 1603, his territories were inherited by his son, Satomi Tadayoshi. However, Satomi Tadayoshi was related by marriage to Ōkubo Tadachika, and was implicated in the Ōkubo Nagayasu Incident of 1614, which the Tokugawa shogunate used as excuse to abolish Tateyama Domain and extinguish the Satomi clan.

In 1617, the Tokugawa shogunate established Naitō Kiyomasa as a fudai daimyō, splitting of 30,000 koku of the former Satomi territories centered at Katsuyama and was allowed to build a jin'ya fortified residence, but not a full castle. He was followed by his son Naitō Masakatsu, who ruled until 1629. Naitō Masakatsu’s son Naitō Shigeyori resigned administration of the domain to assume the post of Osaka jōdai; as his heirs were underage at the time of his death, the domain reverted to tenryō status.

In 1668, Sakai Tadakuni who had risen through the administrative ranks within the Tokugawa shogunate, gained the requisite 10,000 koku in revenue to become daimyō and was permitted to revive the defunct Awa-Katsuyama Domain. His descendants continued to rule Awa-Katsuyama Domain until the Meiji Restoration. With the abolition of the han system in July 1871, Awa-Katsuyama Domain briefly became “Katuyama Prefecture”, which later became part of Chiba Prefecture.

• Papinot, E (1910). Historical and Geographic Dictionary of Japan. Tuttle (reprint) 1972.

• (in Japanese) Awa-Katsuyama on "Edo 300 HTML"