Ikoma Chikamasa


Ikoma Clan

Sanuki Province

Ikoma Chikamasa

Lifespan:  Daiei 6 (1526) to 2/13 of Keichō 8 (1603)

Other Names:  Masanari, Toda Jinsuke (common), 近規, Masakatsu

Rank:  bushō, daimyō

Title:  Junior Fifth Rank (Lower), Junior Fourth Rank (Lower), Director of the Bureau of Cultural Affairs

Clan:  Ikoma

Bakufu:  Edo

Domain:  Lord of Sanuki-Takamatsu

Lord:  Oda Nobunaga → Toyotomi Hideyoshi → Toyotomi Hideyori

Father:  Ikoma Chikashige

Mother:  Daughter of the Sone clan

Siblings:  Chikamasa, Chikakiyo, Katsusuke (Ichizaemon), Surinosuke, Jiemon, Genhachirō

Wife: [Formal] Adopted daughter of Takagi Masasuke

Children:  Kazumasa, daughter (second wife of Murakoshi Naoyoshi)

Ikoma Chikamasa served as a bushō and daimyō from the Sengoku to early Edo periods.

Chikamasa was one of three daimyō known as the sanchūrō, a senior role established toward the end of the Toyotomi administration responsible for mediating differences of opinion between the gotairō, or Council of Five Elders, and the gobugyō, or Five Commissioners.  The other two members of the sanchūrō were Horio Yoshiharu and Nakamura Kazuuji.

Chikamasa was born as the son of Ikoma Chikashige in Toda in the Kani District of Mino Province.

In 1566, Chikamasa served as a retainer of Oda Nobunaga during an invasion of Mino.  Thereafter, he was assigned to serve as a bushō under the command of Hashiba Hideyoshi, participating, among other conflicts, in the Battle of Kanegasaki in 1570, the Battle of Nagashino in 1575, the Ishiyama War against the Ishiyama-Hongan Temple from 1570 to 1580, and the war against the Saika group of Kii Province in 1577.

In 1582, after the death of Oda Nobunaga in a coup d’état known as the Honnō Temple Incident, Chikamasa became a retainer of Hideyoshi.  He served in the Battle of Yamazaki in 1582, the Battle of Shizugatake in 1583, the Conquest of Odawara in 1590, and the Bunroku Campaign on the Korean Peninsula.  Beginning in the era when Hideyoshi was serving as the lord of Himeji Castle in 1578, Chikamasa received a stipend of approximately 1,000 koku.  This steadily increased to 2,000 koku in 1578, to 23,500 koku in 1585, and to 60,000 koku in 1586 in Kariya in Harima Province.

In 1595, Chikamasa received 126,000 koku in Sanuki Province whereupon he built Takamatsu and Marugame castles and established a town below the castles.  At Marugame, accompanying the construction of the castle, he developed a castle town centered around an area called the three inlets of Kitahirayama, Nishihirayama, and the Gokusho-machi, and another area comprised of the towns of Nanjōmachi, Honmachi, and Shiwakumachi.

During the later years of Hideyoshi’s life, Chikamasa, together with Nakamura Kazuuji and Horio Yoshiharu, was appointed as a member of the sanchūrō, participating in the Toyotomi administration.  Under an alternate theory, the sanchūrō function did not actually exist and was a creation of later eras.

In 1600, at the Battle of Sekigahara, his son, Ikoma Kazumasa, served in the Eastern Army.  Meanwhile, Chikamasa remained in Sanuki but joined the Western Army and sent a retainer on his behalf for the Siege of Tanabe Castle in Tango Province.  There are various theories regarding why he Joined the Western Army including that he did not have a choice because, at the time of formation of the Western Army, he was stationed in Ōsaka, or that he considered how the Ikoma family could survive without regard to which side loses the battle.

After the war, he underwent the rites of tonsure and went to Mount Kōya.  While it is said this was to take responsibility for joining the Western Army, he went to Mount Kōya prior to the main battle at Sekigahara so there is a theory that he was questioned for actions taken in favor of the Eastern Army.

Later, owing to Kazumasa’s participation in the Eastern Army, the lkoma family received official recognition of their landholdings.  After the conduct of a land survey and adjustment to the value of his landholdings, the yield of the Sanuki-Takamatsu domain held by Kazumasa was 173,000 koku.  Before long, he returned to Sanuki and, in 1603, died in Takamatsu Castle.


Chikamasa took custody of and raised Sogō Senmatsumaru, the lineal heir of Sogō Masayasu, the former kokushu, or lord, of Sanuki who died at the Battle of Hetsugigawa against the Shimazu clan.  In 1587, when Chikamasa accompanied Senmatsumaru in a visit to Hideyoshi, Hideyoshi questioned why the son of the caliber of the Sogō only held 3,000 koku, whereupon discussion suddenly arose among the surviving retainers that the fief be restored to 20,000 koku.  Senmatsumaru, however died of illness at the age of fifteen in the year that he approached his coming-of-age ceremony.  His early death triggered a rumor that he had been poisoned by Chikamasa’s nephew, Ōtsuka Uneme who performed a dance on stage along with Senmatsumaru in front of Hideyoshi.

According to one theory, this was a stratagem by an enemy of the Ikoma family to impoverish them.  Later, to forestall the revival of the Sogō clan, the Ikoma family is known to have suppressed persons related to the Miyoshi clan.