Lifespan: Eishō 5 (1508) to 2/2 of Tenbun 18 (1549)
Other Names: Magojirō (common)
Rank: bushō, daimyō
Title: Governor of Sanuki
Father: Sōma Moritane
Siblings: Akitane, Horiuchi Chikatane, Kuroki Tanenori
Wife: Yakata-gozen (eldest daughter of Date Tanemune)
Children: Moritane, Okita (formal wife of Tamura Kiyoaki)
Sōma Akitane served as a daimyō during the Sengoku period. He was the fourteenth head of the Sōma clan.
Akitane was born as the son of Sōma Moritane, the thirteenth head of the Sōma clan of Mutsu Province. Akitane wed the eldest daughter of Date Tanemune (the fourteenth head of the Date clan). In 1521, at the age of fourteen, he inherited the headship of the clan.
On 6/11 of Entoku 4 (1492), Akitane’s grandfather, Sōma Takatane, died while deployed in battle against Shineha Takanari. Akitane’s father, Moritane, succeeded Takatane and, after regrouping, recommenced operations against the Shineha clan. In the twelfth month, Moritane captured the base of the Shineha at Gongendō Castle and decimated the clan. He then took command of the Shineha District along with Tomioka and Kido castles in the Naraha District of Mutsu. Later, these bases were forcibly taken by the Iwaki clan, but, in 1524, recaptured by Akitane. He assigned his younger brother, Saburō Tanenori (Noritane) to serve as the chamberlain of Tomioka Castle and Shimoura Yasukiyo from one of the most powerful families in the Shineha clan to serve as the chamberlain of Kido Castle.
During the Tenbun Conflict – a series of clashes continuing from Tenbun 11 to Tenbun 17 (1542 to 1548) between supporters of Date Tanemune and those of his eldest son, Date Harumune – Akitane, along with Kakeda Toshimune and Kakeda Yoshimune (father and son), and Tamura Takaaki, served as key supporters of Tanemune.
Akitane and Kakeda Yoshimune once rescued Tanemune from Nishiyama Castle and moved to Kakeda Castle. Later, Harumune incarcerated Tanemune in Nishiyama Castle a second time so Akitane attempted to negotiate but Harumune refused to engage so the two sides clashed in battle.
In a letter addressed to Hasekura Shinbei from the ninth month of 1543, Tanemune praised the Sōma for their heroic deployment to Kakeda, indicating that Akitane himself had taken command and applied pressure on Harumune. A battle at Ōmori Castle in Shinobu resulted in the deaths of over one hundred of Harumune’s troops and over sixty Sōma troops including Okada Tanemichi. During another battle at Hirasawa, over thirty were killed including Mizugai Shikibu (perhaps the father of Mizugai Taneshige) and Aota Noto. In battle at 高子原 in the Date District, he defeated the army of Harumune, rescued Tanemune from Nishiyama Castle, and transferred him to Odaka Castle.
Historical accounts from the Date clan do not make reference to Tanemune’s entry to Odaka Castle, but, in a letter from Harumune to Iwaki Shigetaka from the sixth month of 1545, he notes that Akimune accompanied his father-in-law, Tanemune, to enter Odaka Castle. There are also many references to Tanemune’s move to Odaka Castle in sources related to the Sōma family.
Prior to entering the castle, Akitane visited the Dōkei Temple to pray for the souls of those killed in action, holding a Buddhist memorial service for seventeen days. He made condolence calls to the homes of those lost in battle and thanked the peasants in the villages of Onaba and Fukuoka for sending provisions to them during the deployment. At the time, the villages of Onaba and Fukuoka, along with three others, were known as the source of homegrown produce where multi-generational landowners engaged in farming. After entering Odaka Castle, Tanemune moved the following year to Marumori Castle in the Igu District. While passing by Ishimiya in the Chikura manor, he saw a vow previously inscribed by Iwamatsu Yoshimasa in a stone for the Four Heavenly Kings of the Iwamatsu not to betray their family. Based on this impression, he is said to have written on a stone in blank ink an oath for the Sōma not to oppose the Date family for seven generations.
Around 1543, while on deployment in Kakeda, Kuroki Danjō Masafusa and Nakamura Daizen Yoshifusa (siblings) revolted and attempted to assault Tanaka Castle in Kitagō whereupon they were subdued and Akitane took control of Uda Province. He then assigned Kusano Naokiyo to Sōma-Nakamura Castle and Aota Shinano to serve as the chamberlain of Kuroki Castle. In this manner, his authority extended to the Uda, Namekata, and Shineha districts of Mutsu, serving as the foundation for the Sōma as a sengoku daimyō family.
On 2/2 of Tenbun 18 (1549), Akitane died in Odaka. He was succeeded by his lineal heir, Sōma Moritane, who became the fifteenth head of the clan. Moritane had the same name (written with the same characters) as his grandfather (Akitane’s father) who served as the thirteenth head of the clan.
Akitane stood at over 180 centimeters and was a brave warrior said to have the strength of eight men and able to freely wave a commander’s war fan made of steel.
A refined individual, Akitane had a deep fondness for the citizens of his territory. He did not invade other provinces while other clans reciprocated by completely excluding invasions of the Sōma territory.