Inaba Masanari

Who They Were

Inaba Masanari (稲葉正成, いなば まさなり) was a samurai who lived from 1571 to 14 October 1628, a career that carried him across one of the most violent and decisive stretches of Japanese history. He was born in the second year of the Genki era (元亀, げんき), during the Muromachi period, and died in the early Edo period, having outlived the civil wars that made his name. He served three successive powers — the Oda, the Toyotomi, and the Tokugawa — and ended his life as a daimyō (大名, だいみょう), a territorial lord holding land and retainers in his own right.

He is remembered today less for a single battle than for his marriages and his descendants. His wife was Kasuga-no-Tsubone (春日局, かすがのつぼね), one of the most powerful women in early Tokugawa Japan, and through her and his sons he became the founder of a lineage that remained prominent in the Tokugawa order for two and a half centuries.

Life and Career

Masanari was the son of Hayashi Masahide (林政秀, はやし まさひで). He entered military life in the closing decades of the Sengoku period, the era of near-constant warfare between regional lords. His recorded campaigns include the Siege of Odawara, the Shikoku Campaign, the Second Japanese Invasion of Korea, and the Battle of Sekigahara.

The Siege of Odawara, fought in 1590, was Toyotomi Hideyoshi's destruction of the Hōjō clan's great fortress at Odawara, the campaign that completed his unification of Japan. The Shikoku Campaign was Hideyoshi's subjugation of the island of Shikoku. The Second Japanese Invasion of Korea was the second of Hideyoshi's two large expeditions against the Korean peninsula in the 1590s. The Battle of Sekigahara, fought in 1600, was the decisive engagement in which Tokugawa Ieyasu defeated a coalition of rival lords and effectively took control of the country. A samurai who fought in all four of these campaigns served at the centre of the unification wars, under Oda, Toyotomi, and finally Tokugawa banners in turn.

In the Edo period he held the position of daimyō. He married Kasuga-no-Tsubone, who bore him sons, and the couple later divorced. The divorce did not end their connection: they remained on good terms as parents to their shared children. After the separation Kasuga became wet-nurse to the eldest son of Tokugawa Hidetada, the second Tokugawa shōgun — a position that placed her at the heart of the shogunal household and gave her lasting influence over the heir.

Masanari died on 14 October 1628. His sons Inaba Masakatsu and Inaba Masatsugu carried the family name forward.

Why They Matter

Masanari's importance is inseparable from the household he helped create. The Inaba were counted among the fudai (譜代, ふだい), the hereditary vassal clans of the Tokugawa, as opposed to the tozama (外様, とざま), the outsider lords who had submitted to Tokugawa rule only after defeat. That distinction shaped who could hold office in the shogunate, and it made the Inaba a permanent part of the governing establishment rather than a conquered province.

His marriage to Kasuga-no-Tsubone tied him to one of the great political figures of the age. As wet-nurse to Tokugawa Hidetada's eldest son, Kasuga raised the boy who would become the third shōgun, Tokugawa Iemitsu. Her standing gave the Inaba line a channel of influence into the shogunal court that few warrior houses could match.

The family's later history shows how far that influence reached. Masanari's grandson Inaba Masayasu (稲葉正休, いなば まさやす), who lived from 1640 to 1684, is remembered chiefly as the wakadoshiyori (若年寄, わかどしより) — a senior shogunal official — who assassinated the tairō (大老, たいろう) Hotta Masatoshi. The tairō was the highest office in the shogunate below the shōgun himself, and the killing of one by a serving official was one of the most startling political acts of the Edo period.

The Name in Japanese

The name is written 稲葉正成 and read いなば まさなり in kana, romanised as Inaba Masanari. The family name comes first, as is standard in Japanese.

稲 (いな, ina) — "rice plant," specifically the growing plant in the paddy rather than the harvested grain. It is the same character used in 稲荷 (いなり, Inari), the rice deity.

葉 (ば, ba) — "leaf." Read alone the character is は (ha); after another kanji it voices to ば, which is why the surname is Inaba and not Inaha. Together, 稲葉 evokes rice plants and their leaves — an agricultural image, fitting for a name that originated among landholding families.

正 (まさ, masa) — "correct," "right," "proper." It appears constantly in samurai given names of this period, often as the first element of a two-character name.

成 (なり, nari) — "to become," "to accomplish," "to complete." Paired with 正, it forms Masanari, a name carrying the sense of right conduct brought to completion.

The full name therefore reads as a surname drawn from the rice field and a given name built from two characters meaning correctness and accomplishment. Masanari also appears in some sources under the alternative reading Inaba Masashige, and he was sometimes styled Mino-no-kami (美濃守, みののかみ), a court title meaning "Governor of Mino," a province corresponding roughly to the southern part of modern Gifu Prefecture. Such titles were honorific rather than administrative, but they signalled rank within the warrior hierarchy.

Legacy

The Inaba clan's standing as fudai daimyō gave it a durable place in the Tokugawa system, and Masanari stands at the head of that line. His sons Inaba Masakatsu and Inaba Masatsugu continued the family, and his descendants remained among the insider houses on which the shogunate relied.

His most lasting mark, though, runs through Kasuga-no-Tsubone. The wet-nurse he divorced became one of the defining figures of the early Tokugawa court, and the children they raised together linked the Inaba name to the shogunal family itself. The grandson who killed the tairō Hotta Masatoshi carried that name into the most sensational political episode of the seventeenth-century shogunate. From a samurai who fought through Odawara, Shikoku, Korea, and Sekigahara, the family rose to sit at the centre of the Edo order — and stayed there.