Inaba Masakatsu

Who They Were

Inaba Masakatsu (稲葉正勝) was a daimyō — a territorial lord — of early Edo-period Japan, born in 1597 and dead on 22 February 1634. He held three domains in succession: Kakioka in Shimōsa Province, Mōka in Shimotsuke Province, and finally Odawara Domain in Sagami Province. He also served in the Tokugawa shogunate's senior council, the Rōjū.

His parentage placed him at the centre of the shogunate's inner circle. His father was Inaba Masanari, a senior Tokugawa retainer, and his mother was Lady Kasuga, the wet nurse of the third shogun Tokugawa Iemitsu and later one of the most powerful figures in the Ōoku, the shogun's inner palace. Masakatsu's son, Inaba Masanori, continued the line.

Masakatsu's life was short — he died at thirty-six or thirty-seven — but it spanned a decisive stretch of Japanese history. He was born under the Keichō era (慶長, keichō), in its second year, when the country was still formally in the Azuchi–Momoyama period. By the time he reached adulthood, the Tokugawa had won at Sekigahara and established a shogunate in Edo that would last more than two and a half centuries.

Life and Career

Masakatsu was born in 1597, the son of Inaba Masanari and Lady Kasuga. His mother's position was extraordinary. She had been appointed wet nurse to Tokugawa Iemitsu, the grandson of the founder of the shogunate, and her influence over the heir gave the Inaba family a standing that most daimyō could not match. Masakatsu grew up inside that orbit.

He became a daimyō and was granted Kakioka Domain in Shimōsa Province. He was later transferred to Mōka Domain in Shimotsuke Province, and finally to Odawara Domain in Sagami Province. Odawara was a major posting: the castle there controlled the Tōkaidō, the great coastal highway linking Edo with Kyoto, and its lords were counted among the most important in the Kantō region.

Alongside his territorial role, Masakatsu served as a Rōjū (老中, rōjū) — one of the senior councillors who advised the shogun and managed the day-to-day business of the shogunate. The Rōjū sat near the top of the Tokugawa administrative machine, handling matters of policy, justice, and relations with the great lords. For a man who died in his mid-thirties, holding that office was a rapid ascent, and it reflected both his mother's standing and his own place in the shogunate's trusted circle.

Masakatsu died on 22 February 1634. His son, Inaba Masanori, succeeded him.

Why They Matter

Masakatsu matters less for a single dramatic act than for what his career shows about how power worked in early Edo Japan. The Tokugawa shogunate governed through a network of daimyō bound to the regime by land, marriage, and personal service. Masakatsu sat at the intersection of all three: a domain lord, a senior councillor, and the son of the woman who had raised the shogun.

His mother, Lady Kasuga, became one of the most consequential women in Tokugawa history, shaping the Ōoku and the succession politics around Iemitsu. Masakatsu's own rise — three domains and a seat on the Rōjū before his death at thirty-six — is a direct measure of how far that connection could carry a family.

His line endured. Through his son Inaba Masanori, the Inaba name remained embedded in the shogunate's governing class, and the family's association with Odawara gave it a lasting place in the geography of Tokugawa power.

The Name in Japanese

The name is written 稲葉正勝. In kana it is read いなば まさかつ, and in romaji, Inaba Masakatsu. The family name comes first, as is standard in Japanese; the given name follows.

Breaking it down character by character:

• 稲 (いな, ina) — "rice plant." This is the first character of the surname. It depicts a rice plant and is the same character used in 稲作 (inasaku), rice cultivation.
• 葉 (ば, ba) — "leaf." Combined with 稲, it forms 稲葉 (Inaba), literally "rice leaves." The reading shifts from the standalone は (ha) to ば (ba) in this compound, a common voicing change in Japanese.
• 正 (まさ, masa) — "correct," "right," "just." This is the first character of the given name. It appears in many samurai names of the period, where it carried connotations of uprightness and propriety.
• 勝 (かつ, katsu) — "victory," "to win." The second character of the given name. It is a frequent element in warrior names, and it also appears in the verb 勝つ (katsu), "to win."

So the surname 稲葉 means "rice leaves," and the given name 正勝 carries the sense of "correct victory" or "righteous victory." The full name, Inaba Masakatsu, is thus a compound of an agricultural surname and a given name built from two auspicious warrior characters.

One point worth noting for learners: the kana reading いなば まさかつ shows the voicing of は to ば in the surname, and the given name is read with all four characters in their kun'yomi (native Japanese) readings rather than their Chinese-derived on'yomi. Names frequently mix these systems, so a character's reading in a name cannot always be predicted from its dictionary readings alone.

Legacy

Masakatsu's legacy runs through two channels: his family and his office. The Inaba house, already prominent through his father Masanari and his mother Lady Kasuga, continued under his son Inaba Masanori, keeping the family within the shogunate's governing elite.

His tenure at Odawara tied the Inaba name to one of the most strategically important castles in eastern Japan, on the Tōkaidō between Edo and the west. And his service as Rōjū placed him among the small group of men who ran the Tokugawa state in its formative decades.

He died young, in 1634, before the shogunate had reached even its third decade under Iemitsu. What he left behind was a family positioned at the heart of Tokugawa government — a position built as much on his mother's extraordinary career as on his own.