Lifespan: Eishō 9 (1512) to Eiroku 4 (1561)
Title: Hōki-no-kami (Governor of Hōki)
Lord: Nagao Tamekage → Nagao Kagetora (Uesugi Kenshin)
Father: Shibata Nagatsuna
Children: Nagaatsu, Shigeie, Moriyoshi, daughter (wife of Ijimino Nobumune), daughter (wife of Irobe Nagazane)
Shibata Tsunasada served as a bushō during the Sengoku period.
In 1512, Tsunasada was born as the son of Shibata Nagatsuna.
The Shibata clan were kokujin, or provincial landowners, in the northern portion of Echigo Province. The Shibata were members of the Agakita Group. The families comprising the Agakita Group defended their local authority in the northern portions of Echigo from the Kamakura to Sengoku periods. Agakita refers to the region to the north of the Agano River in Echigo. The Shibata were an illegitimate branch of the Kaji clan who were the main branch of the Sasaki party founded by Sasaki Moritsuna, a bushō from the late Heian period. The Sasaki party also included the Shibata, the Takenomata, and the Ijimino clans.
Tsunasada served as the lord of Ijimino Castle. After Nagao Tamekage, the deputy military governor and sengoku daimyō of Echigo, toppled the Uesugi clan and focused on the pacification of Echigo, Tsunasada followed him.
In the sixth month of 1503, Jōjō Sadazane received the daughter of Uesugi Fusayoshi, the military governor of Echigo, as his formal wife and became Fusayoshi’s son-in-law, changing his name to Uesugi Sadazane. In the eighth month of 1507, Nagao Tamekage gave support to Sadazane to oust Fusayoshi. On 11/6 of 1508, Sadazane became the military governor but, in fact, was a puppet of Tamekage. Around this time, Sadazane wed the younger sister of Tamekage. His formal wife, Fusayoshi’s daughter, is believed to have died as of this time.
Gradually, however, Sadazane came to resent serving as a puppet for Tamekage. In 1513, he assembled forces comprised of Usami Fusatada and Usami Sadamitsu (father and son) who were lineal retainers of the family of the military governor, Jōjō Sadanori from the main Jōjō clan (who was either a younger brother or nephew), and several clans from the Agakita Group, triggering the Jōjō Revolt. Tsunasada, together with, among others, Honjō Fusanaga, Ayukawa Kiyonaga, Mizuhara Masaie, Kurokawa Kiyozane, Nakajō Fujisuke, Ijimino Kageie, Kaji Harutsuna, and Takenomata Masatsuna, betrayed Tamekage.
Sadazane occupied Kasugayama Castle to direct ongoing resistance, but failed and was temporarily incarcerated resulting in a loss of influence. Thereafter, Sadanori and others came together again to oppose Tamekage, and, on 8/3 of 1536, forced Tamekage into retirement, but did not go so far as to enable Sadazane to grasp power. In any event, Tamekage’s successor, Nagao Harukage, could not attract wide support so Sadazane’s authority showed signs of being restored. Conflict persisted across Echigo until its unification under Nagao Kagetora in 1551. In the end, Tsunasada became a retainer of Kagetora.