Lifespan: Bunmei 16 (1484) to 7/27 of Tenbun 2 (1533)
Title: Assistant Captain of Outer Palace Guards of the Left Division
Father: Satomi Yoshizane or Satomi Shigeyoshi
Mother: Daughter of the Miura-Yokosuka clan
Siblings: Yoshitomi, Yoshimichi, Sanetaka, Tōjō Sanetomo, sister (wife of Satomi Yoshimasa), sister (wife of Karasuyama Tokisada), sister (wife of Horiuchi Masakane)
Wife: Daughter of Sakuma Moriuji
Satomi Sanetaka served as a bushō during the Sengoku period. He was a member of the Satomi clan of Awa Province.
According to the genealogy, Sanetaka was born as the second son of Satomi Shigeyoshi, the second head of the Satomi clan. After the death of his older brother, Satomi Yoshimichi, Sanetaka inherited the headship of the clan or served as a guardian and proxy for his nephew, Satomi Yoshitoyo. Based on recent research, however, this is deemed to be a fabricated history to justify the succession by Sanetaka’s lineal heir, Satomi Yoshitaka, to the head of the clan. Moreover, it is surmised that Sanetaka, along with his older brother, Yoshimichi, were the sons of Satomi Yoshizane, the first head of the Awa-Satomi clan.
Upon orders of Yoshimichi, Sanetaka advanced into Kazusa Province. Based at Kanaya Castle, he garnered control of the navy for the Bōsō Peninsula including the Masaki clan. In the era of Yoshitoyo, he obeyed orders to attack Kamakura and Musashi-Shinagawa, fighting against the Gohōjō clan. Gradually, as he gained influence in the family, Sanetaka posed a threat to the authority of Yoshitoyo and, in addition, rumors circulated of collusion with the Gohōjō via his close associate, Masaki Michitsuna.
As a result, in 1533, Yoshitoyo attacked and murdered Sanetaka and Michitsuna at Inamura Castle. There is also a theory that Michitsuna managed to escape but died later of his injuries. Under the banner of avenging the death of his father, Sanetaka’s eldest son, Satomi Yoshitaka, joined with Masaki Tokishige (the orphan of Michitsuna) and rebelled against Yoshitoyo. In the course of a conflict that ebbed and flowed, Yoshitoyo initially defeated Yoshitaka, but Yoshitaka then counterattacked, driving Yoshitoyo to Kazusa Province. The next year, Yoshitoyo received support from Mariyatsu Jokan (Nobukiyo) of the Takeda clan and returned to Awa, but at the Battle of Inukake, incurred a major defeat and took his own life. He was twenty-one years old. This is referred to as the Inamura Incident or, alternatively, as the Tenbun Discord.
In 1534, Yoshitaka claimed the headship and became the fifth head of the Satomi clan.
Based on a former interpretation of events, Yoshimichi died at a young age when Yoshitoyo was still in his youth so, until he matured, Sanetaka (his uncle) served as his guardian and proxy in battle. After growing up, Yoshitoyo indiscriminately resented the role of Sanetaka and murdered him. Recent research has shown that Yoshimichi did not die early and, instead, transferred the headship of the clan to Yoshitoyo as an adult and then retired. At the time of the Inamura Incident, it is surmised that Yoshitoyo was in the prime of his life. Therefore, the current view is that this story was fabricated to emphasize the propriety of succession to the headship of the clan by Yoshitaka as the lineal heir of Sanetaka. Sanetaka is not currently deemed to have served as either the head of the clan or as a proxy for Yoshitoyo.