Saitō Toshimitsu

Who They Were

Saitō Toshimitsu (斎藤利三, さいとう としみつ) was a samurai commander who lived from 1534 to 1582, serving through the final decades of the Muromachi period (1336–1573) and into the upheavals that ended it. He was born in Mino Province, in the region that is now southern Gifu Prefecture, and he held Kuroi Castle as his base. His career is remembered chiefly for two things: his role in the Honnō-ji Incident of 1582, and his daughter, Lady Kasuga, who became one of the most powerful figures in the early Tokugawa shogunate.

Toshimitsu's life sits at the hinge of Japanese history. The Muromachi period, dominated by the Ashikaga shogunate in Kyoto, had collapsed into a century of civil war among regional warlords. Men like Toshimitsu — skilled, ambitious, and willing to change masters — were the raw material of that conflict. He began as a retainer of Inaba Ittetsu, a lord of Mino, and later entered the service of Akechi Mitsuhide, the general whose name is inseparable from the most famous assassination in Japanese history.

Life and Career

Toshimitsu was born in 1534, in the third year of the Tenbun era (天文), during the reign of Emperor Go-Nara. His father was Saitō Toshikata, and his mother was a daughter of Ninagawa Chikamasa. His family name, Saitō, tied him to the Saitō clan that had once dominated Mino Province. He married a daughter of Saitō Dōsan, the notorious "viper of Mino" who had risen from oil merchant to warlord, and he also took Inaba Yasu as a wife.

His early career was spent in the service of Inaba Ittetsu, one of the "Mino Three" — the trio of commanders who governed Mino after Oda Nobunaga absorbed it. At some point Toshimitsu transferred his loyalty to Akechi Mitsuhide, a decision that nearly cost him his life. Oda Nobunaga, who ruled central Japan with increasing ruthlessness, was displeased that Toshimitsu had entered Mitsuhide's service, and only Mitsuhide's personal intervention saved him from execution. That debt of gratitude shaped everything that followed.

In 1582, Mitsuhide turned on his own lord. On the night of the Honnō-ji Incident, Mitsuhide's forces surrounded the Kyoto temple where Nobunaga was staying with a small guard, and Nobunaga was forced to take his own life. Toshimitsu was one of the commanders central to the operation. Weeks later, at the Battle of Yamazaki, Mitsuhide's army met the forces of Toyotomi Hideyoshi and was destroyed. Toshimitsu died on July 6, 1582, at the Rokujō Riverbed in Kyoto, alongside his master's collapsing cause.

Why They Matter

Toshimitsu matters because he was present at the exact moment the unification of Japan changed hands. Nobunaga had spent two decades destroying the old order; his death at Honnō-ji in 1582 opened the struggle that ended with Toyotomi Hideyoshi and then Tokugawa Ieyasu completing the job. Toshimitsu was not a warlord in his own right, but he was a senior commander in the coup that triggered that transition, and he died in the battle that decided it.

He also matters through his children. His daughter, Lady Kasuga (春日局), became the wet nurse and later the senior confidante of Tokugawa Iemitsu, the third Tokugawa shogun. From that position she exercised enormous influence over the shogunate's inner court, and her descendants and connections wove the Saitō name into the fabric of Tokugawa rule. A man who died on the losing side at Yamazaki ended up, through his daughter, as an ancestor of the regime that ruled Japan for two and a half centuries.

The Name in Japanese

The full name is written 斎藤利三. It is read さいとう としみつ in kana, and romanised as Saitō Toshimitsu. Note the long vowel in the family name: Saitō, not Saito.

斎 (さい, sai) — This kanji means "purification," "abstinence," or "a purified room." It appears in Shintō vocabulary for ritual purity and in words for religious observance. In the surname 斎藤 it is the first element, and it is read sai.

藤 (とう, tō) — This kanji means "wisteria," the climbing vine with hanging purple flowers. It is one of the most common elements in Japanese surnames, appearing in 藤原 (Fujiwara), 佐藤 (Satō), 伊藤 (Itō) and many others. Here it is read tō, and it combines with 斎 to give the surname 斎藤, Saitō. The long ō comes from the combination of sa + i + tō.

利 (とし, toshi) — This kanji means "profit," "benefit," "advantage," or "sharp." It is a common element in male given names. In 利三 it is read toshi, the first part of the given name.

三 (みつ, mitsu) — This kanji means "three." It is the numeral, and it appears frequently as the final element of male given names, where it is read mitsu (or zō, saburō and other readings in different names). In 利三 it is read mitsu, giving the given name 利三, Toshimitsu.

So the name breaks down as: surname 斎藤 (Saitō, "purification" + "wisteria"), given name 利三 (Toshimitsu, "profit/advantage" + "three"). The pattern — a two-kanji surname followed by a two-kanji given name — is the standard shape of a samurai name, and it is the same shape as the names of nearly every figure in this period.

Legacy

Toshimitsu's direct legacy is his daughter. Lady Kasuga (1579–1643), born to Toshimitsu and raised after her father's death in the chaotic years that followed, entered the Tokugawa household as wet nurse to the young Tokugawa Iemitsu. She became ōoku — the mistress of the shogun's inner palace — and a political force in her own right, credited with securing Iemitsu's succession and shaping the shogunate's court culture. Through her, the Saitō line entered the highest circles of Edo-period Japan.

His sons and other daughters also carried the family forward. Saitō Toshimune, his son, continued the Saitō name, and two of his daughters married into the Shibata clan. The family that had fought and lost at Yamazaki in 1582 was, within two generations, embedded in the victorious regime.

For students of Japanese, Toshimitsu's name is a useful case study: it shows the standard samurai naming pattern, the long-vowel convention in romanisation, and the way a single kanji — 藤, wisteria — recurs across hundreds of Japanese surnames. It also shows how history remembers people: not always for what they did, but for who they left behind.