Saigusa Moritomo

Who They Were

Saigusa Moritomo (三枝昌貞) was a samurai of the Sengoku period (戦国時代, sengoku jidai — "Warring States period"), the century and a half of near-constant civil war that ended the Muromachi period and preceded the unification of Japan under Tokugawa Ieyasu. He was born in 1537 and died on 29 June 1575, at the Battle of Nagashino. He is remembered chiefly as one of the "Twenty-Four Generals of Takeda Shingen" (武田二十四将, Takeda nijūyon-shō), a group of senior retainers of the Takeda house of Kai Province.

His father was Saigusa Torayoshi (三枝虎吉). The family name is written 三枝 and read Saigusa; the same characters are also read Saegusa, and both romanisations appear in English-language writing.

Life and Career

Moritomo was born in 1537, in the sixth year of the Tenbun era (天文, tenbun — a nengō or era name, used to number years in the pre-modern Japanese calendar). He served the Takeda clan, the warrior house led by Takeda Shingen (武田信玄, 1521–1573) and, after Shingen's death, by his son Takeda Katsuyori (武田勝頼, 1546–1582).

His marriage tied him to one of the most formidable commanders in the Takeda ranks. He was the son-in-law of Yamagata Masakage (山県昌景, 1524–1575), a senior Takeda general celebrated for the speed and discipline of his cavalry and for the red-lacquered armour worn by his troops. Marriage into a retainer's family was a standard instrument of Takeda policy: it bound lesser houses to the clan's inner circle and gave the sons of those houses a stake in its fortunes.

Moritomo fought under the Takeda banner at the Battle of Mikatagahara (三方ヶ原の戦い, Mikatagahara no tatakai) in 1572, in which Shingen defeated Tokugawa Ieyasu. Three years later he was present at Nagashino (長篠の戦い, Nagashino no tatakai) in Mikawa Province, where Katsuyori attacked the allied army of Tokugawa Ieyasu and Oda Nobunaga. The Takeda assault on the allied stockade failed, and the Takeda force was destroyed. Moritomo died in the fighting on 29 June 1575. His father-in-law Yamagata Masakage died in the same battle.

Why They Matter

Moritomo's historical importance is inseparable from the two battles in which he fought. Mikatagahara was Shingen's greatest victory and one of the few occasions on which Tokugawa Ieyasu was comprehensively beaten in the field. Nagashino, three years later, was the battle that broke the Takeda clan's military reputation: the massed volleys of the Oda–Tokugawa matchlock gunners against the Takeda cavalry charge became, in later retellings, a symbol of the arrival of firearms as a decisive force in Japanese warfare. Moritomo's death there places him among the many senior Takeda retainers killed in a single afternoon, a loss from which the house never recovered.

His inclusion among the Twenty-Four Generals marks him as one of the men on whom the Takeda war machine depended. The list itself was a later construction, compiled to celebrate the clan's martial tradition, and it is through that tradition — rather than through any surviving account of his individual deeds — that Moritomo is known.

The Name in Japanese

The full name is written 三枝昌貞. Its kana reading is さいぐさ まささだ, and its romaji is Saigusa Masasada. Note that the given name in the heading of this page, Moritomo, is a different reading of the same characters 守友 used in some sources; the form 昌貞 read Masasada is the one given above.

三 — read さ (sa) in this name. The character means "three". In Japanese numerals it is the basic digit 3, and it appears in countless compounds: 三月 (sangatsu, March), 三角 (sankaku, triangle).

枝 — read ぐさ (gusa) here, a voiced form of kusa. The character means "branch" or "bough". The compound 三枝, literally "three branches", is an old family name; the image is of a tree spreading into three limbs, a fitting emblem for a warrior house.

昌 — read まさ (masa). The character means "prosperous", "flourishing", "bright". It is a common element in samurai given names, where it carries the sense of a house thriving and growing strong.

貞 — read さだ (sada). The character means "upright", "loyal", "chaste", "correct". It is one of the most frequent closing elements in warrior names of the period, and it signals fidelity and rectitude — the virtues a retainer was expected to embody.

Taken together, the name reads as a compact statement of a warrior's aspirations: a branch of a flourishing house, upright and loyal. The structure is typical of Sengoku-period naming. The surname comes first, as it does throughout Japanese; the given name follows. The given name is two characters, each with its own meaning, and the two are read together as a single word — Masasada — rather than as separate elements.

Legacy

Moritomo left no body of writings and no castle that bears his name. What survives is his place in the roll of the Twenty-Four Generals and the record of his death at Nagashino, where he fell alongside his father-in-law Yamagata Masakage on 29 June 1575. For readers of Japanese history, his name is a convenient entry point into the Takeda retainer network: a son-in-law of one of Shingen's greatest commanders, married into the clan's service, and killed in the battle that ended its ascendancy.