Ikeda Terumasa (January 31, 1565 – March 16, 1613) was a Japanese daimyo of the early Edo period, recognized by his court title, "Musashi no Kami," and known as the "Shogun of Western Japan." Terumasa, a distinguished military leader, participated in numerous significant battles during the late Azuchi-Momoyama period. His service at the Battle of Sekigahara earned him control over the Himeji domain. Originally named Araokojimaru, he was the son of Ikeda Tsuneoki and the brother of Ikeda Sen. He later became the heir to Ikeda Nobuteru and held Ikejiri Castle in Mino Province.
In 1579, during the Siege of Itami, Terumasa and his father guarded Settsukura Bridge, and during the 1580 Siege of Hanakuma Castle, Terumasa distinguished himself in combat by personally defeating six enemies, earning him commendation from Oda Nobunaga. During the Battle of Nagakute in 1584, Terumasa initially fought under Ikeda Tsuneoki and Mori Nagayoshi but ultimately had to retreat following their defeat.
In 1590, following Tokugawa Ieyasu’s move to the Kanto region, Terumasa was awarded a 152,000-koku fief at Yoshida in Mikawa Province. In 1594, he married Tokuhime, daughter of Tokugawa Ieyasu, aligning the Ikeda clan closely with the Tokugawa. That same year, he was involved in logistical support for Hideyoshi’s Korean campaigns and contributed to constructing Fushimi Castle and Yamatotanai Castle for Hideyasu.
After Hideyoshi’s death in 1598, Terumasa allied with Tokugawa Ieyasu, joining a coalition against Ishida Mitsunari, a conflict rooted in disputes over campaign assessments from the Imjin War. While traditionally viewed as a conspiracy to kill Mitsunari, modern historians argue this was a legal dispute mediated by Ieyasu, who intervened to protect Mitsunari from escalation. Tensions between Mitsunari’s faction and Tokugawa supporters contributed to the later Sekigahara conflict.
During the Sekigahara Campaign in 1600, Terumasa supported Tokugawa, convincing Nakagawa Hidenari to do the same. His forces crossed Kawada River and defeated Oda Hidenobu’s forces. At Sekigahara, Terumasa commanded 4,560 troops in the rear guard, facing minor skirmishes with Chosokabe Morichika’s forces. Following the Tokugawa victory, he received the province of Harima and expanded Himeji Castle, completing it in 1609. Bizen Province was added to Terumasa’s territories, which he entrusted to his eldest son, Toshitaka.
By Terumasa’s death in 1613, the Ikeda clan governed an expansive domain that included Harima, Bizen, Inaba, and Awaji, with a combined income of roughly 1,000,000 koku. After Toshitaka’s passing, the Tokugawa Bakufu moved to curtail the Ikeda clan's power, restricting them to the domains of Tottori and Okayama. Terumasa’s legendary katana, known as "Okanehira," was noted for its remarkable size and craftsmanship by Kanehira of Bizen Province, symbolizing the Ikeda legacy.
See also
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Ouchi Yoshihiro
Ōuchi Yoshihiro was the second son of Ōuchi Hiroyo, who headed the Ōuchi clan in the western part of Honshu. In 1363, Shogun Ashikaga Yoshimitsu confirmed the Ōuchi family in the position of shugo of Suō and Nagato Provinces. In his youth, Yoshihiro assisted his father in strengthening the influence of the Northern Court on the island of Kyushu — they served under Imagawa Ryōsun, who had been tasked with subjugating the nine provinces of Kyushu.
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Ouchi Yoshioki
Ouchi Yoshioki, the ruler of the provinces of Suo, Nagato, and Iwami, was one of the most capable military commanders and politicians of the late 15th and early 16th centuries. The son of Ouchi Masahiro, he governed from his residence in Yamaguchi in the province of Suo. In 1499, Yoshioki gave refuge to Shogun Ashikaga Yoshitane, who had been driven out of Kyoto by Hosokawa Masamoto. Shogun Yoshizumi, Masamoto’s protégé, ordered the lords of Kyushu to unite their forces against Yoshioki; however, they did not dare to do so, fearing the power of a man who by that time controlled six provinces. Having gathered a substantial army, Yoshioki marched from his native Suo toward Kyoto in order to restore Shogun Yoshitane to power.
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Otomo Sorin
Ōtomo Yoshishige came from a noble lineage, being the eldest son of Ōtomo Yoshiaki, the ruler of Funai Province. The roots of the Ōtomo family traced back to Fujiwara Hidesato, the adopted son of Nakahara Chikayoshi. Fujiwara served Minamoto Yoritomo during the Genpei War and took part in battles in Mutsu Province in 1189. In 1193, he was appointed shugo of Buzen and Bungo Provinces, after which he adopted a new surname—Ōtomo.
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Okudaira Sadamasa
Sadamasa was the son of Okudaira Sadayoshi and took part in several battles under Tokugawa Ieyasu, distinguishing himself in the Battle of Anegawa in 1570, where he took two heads. Around 1572 he was forced to enter the service of the Takeda clan, but after the death of Takeda Shingen in 1573 he returned to Tokugawa, leaving Tsukude Castle together with his men. As a result of this defection, Takeda Katsuyori ordered the execution of Sadamasa’s wife and brother, who were being held as hostages.
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Okubo Tadatika
Tadatika, the son of Okubo Tadayō, entered the service of Tokugawa Ieyasu at the age of eleven, and took his first head in battle when he was sixteen. After the establishment of the Tokugawa shogunate, he was appointed as a rōjū — a senior bakufu official — and was regarded as one of Ieyasu’s most trusted advisors, alongside Honda Masanobu. He is also known for his military chronicle Mikawa Monogatari, which describes Ieyasu’s rise to power and the early years of the Tokugawa shogunate.
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Okubo Nagayasu
Nagayasu was the second son of Okura Nobuyasu, a sarugaku theater actor from the Takeda clan. Takeda Shingen recognized the young man’s potential and took him into service, appointing him as a vassal to his general, Tsuchiya Masatsugu. During this period, Nagayasu changed his family name to Tsuchiya. He was entrusted with developing the Takeda clan’s gold mines as well as handling matters related to taxation.
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Nitta Yoshisada
Nitta Yoshisada was a loyal soldier of Emperor Go-Daigo, who in the 1330s attempted to restore direct imperial rule in Japan. The Nitta family was related to the Ashikaga house and was older in lineage. However, they did not join Minamoto Yoritomo at the start of his war with the Taira, as the Ashikaga did, and therefore did not receive high positions in the Kamakura shogunate. This may have been one of the reasons why Yoshisada rose against the Hōjō clan in 1333.
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Natsume Yoshinobu
Yoshinobu, a long-time vassal of the Matsudaira and Tokugawa clans, governed Hamamatsu Castle on behalf of the Tokugawa house. During the clashes between the Imagawa, Takeda, and Matsudaira clans, he served in the garrison of Nagasawa Castle and in 1562 took part in raids under the command of Itakura Shigezane. When, in 1563, a revolt of the Sōtō-shū sect followers broke out in Mikawa Province, Yoshinobu joined the rebels together with Honda Masanobu and Hachiya Sadatsugu.
