Ōkubo Tadachika

Who They Were

Ōkubo Tadachika (大久保忠隣) was a samurai and daimyo of the late Muromachi period and the early Edo period. He was born in 1553 in Okazaki, in what is now Aichi Prefecture, the son of Ōkubo Tadayo, a hereditary vassal of the Tokugawa clan. The Ōkubo family served the Tokugawa as fudai daimyo — a category of lords who had been Tokugawa retainers before the clan rose to national power, as opposed to the tozama daimyo who submitted later.

Tadachika's life followed the arc of the Tokugawa ascendancy itself. He fought from his youth, became one of Tokugawa Ieyasu's most trusted advisors, and then fell from power in a political purge. He died in Edo on 28 July 1628.

Life and Career

Tadachika entered service as a samurai at the age of eleven. At sixteen he took his first head in battle — the standard marker of a warrior's coming of age in the Sengoku period, the century of civil war that ran from the mid-fifteenth century until Tokugawa unification.

He grew into one of Ieyasu's most experienced and trusted advisors. His standing was such that he was named alongside Honda Masanobu as one of the inner circle around the future shogun. After the establishment of the Tokugawa shogunate in 1603, Tadachika was appointed rōjū (老中) — a senior councillor of the shogunate, one of the small group of fudai daimyo who handled the day-to-day governance of the regime. He held the domain of Odawara in Sagami Province, a strategically important castle town on the Tōkaidō road.

His political career ended in the affair known as the Ōkubo clan's incidents. The shogunate stripped him of control of most of his domains and sent him into exile. The reversal was total: a man who had helped run the government of Japan lost nearly everything he had accumulated.

Tadachika also wrote, or was associated with, the Mikawa Monogatari (三河物語), a chronicle recording the history of Tokugawa Ieyasu's rise to power and the early years of the shogunate. The text is one of the principal contemporary accounts of how the Tokugawa came to rule.

He had three recorded children: Ōkubo Noritaka, Ishikawa Tadafusa, and Ōkubo Tadatsune.

Why They Matter

Tadachika matters for two reasons that pull in opposite directions. First, he was a maker of the early Tokugawa state: a rōjū at the centre of the shogunate's founding administration, trusted by Ieyasu himself. Second, he is a case study in how fragile even the highest position was under that same regime. The Ōkubo clan's incidents show that proximity to the shogun offered no guarantee of survival; a political misstep could cost a founding councillor his lands and his freedom.

His connection to the Mikawa Monogatari gives historians a window into the Tokugawa rise written from inside the retainer class. The chronicle preserves the perspective of the men who fought for Ieyasu before he was shogun, and it is read today as much for that viewpoint as for its narrative of events.

The Name in Japanese

The full name is written 大久保忠隣.

• Kana reading: おおくぼ ただちか
• Romaji: Ōkubo Tadachika

Broken down character by character:

大久保 (Ōkubo) — the family name, three characters:

• 大 — read here as ō; means "large" or "great."
• 久 — read here as ku; means "long-lasting" or "of long duration."
• 保 — read here as bo; means "protect," "keep," or "preserve."

Together the surname carries a sense of something great and enduring that is kept safe — an auspicious construction typical of warrior family names.

忠隣 (Tadachika) — the given name, two characters:

• 忠 — read here as tada; means "loyalty" or "devotion." This character appears constantly in the names of Sengoku and Edo-period warriors, and it was frequently granted by a lord to a retainer as a mark of favour.
• 隣 — read here as chika; means "neighbour" or "adjacent."

Note that the readings tada and chika are kun'yomi, the native Japanese readings of the characters, rather than the Sino-Japanese readings chū and rin. Warrior names of this period routinely used kun'yomi in this way, which is why the same characters can be read quite differently from one family to the next. A reader who knows only the standard on'yomi would not arrive at "Tadachika" from these two characters.

Legacy

Tadachika's legacy is split between his record as a statesman and the cautionary tale of his downfall. For students of the early Edo period, he represents the generation of fudai daimyo who built the shogunate's institutions and then discovered how quickly those institutions could turn on them. The Ōkubo clan's incidents became a reference point for later Tokugawa politics, a reminder that the shogunate's senior councillors served at the pleasure of the regime.

Through the Mikawa Monogatari, his name is also attached to the written memory of the Tokugawa conquest. The chronicle preserves the voice of the Mikawa retainers — the men from Ieyasu's home province who formed the core of his military following — and it remains a source for how that group understood its own history. Tadachika died in Edo on 28 July 1628, having outlived the power he once wielded.