After Sekigahara, Why Did Only the Shimazu House Escape Reduction of Fief?

After the victory at Sekigahara on October 21, 1600, was decided, Tokugawa Ieyasu began the disposition of Western-side daimyō.

Ishida Mitsunari was executed; Ukita Hideie was exiled to Hachijōjima; Chōsokabe Morichika was forfeited; Mōri Terumoto was greatly reduced from 1,200,000 to 360,000 koku.

Cases of daimyō on the Western side who kept their home fiefs were extremely limited.

Among these, the Shimazu house was confirmed as-is in Satsuma, Ōsumi, and the Morokata District of Hyūga at 770,000 koku.

The only case of complete survival on the Western side.

The disposition of the Shimazu house was not decided immediately after Sekigahara, and negotiations continued for two and a half years thereafter.

The Tokugawa side initially planned complete conquest or major reduction of the Shimazu house.

But that Yoshihiro's retreat combat showed the combat capability of Satsuma troops, that Satsuma was distant from the mainland and the actual conquest would require enormous force and time, and that the Shimazu house showed the posture of responding to negotiation while leaving the head Yoshihisa in place, changed the Tokugawa side's judgment.

In December 1602, the confirmation of the Shimazu house's home fief was officially decided.

The political significance of the 'Sutegamari' retreat combat lay, beyond the success of the combat itself, in making the Tokugawa side recognize the Shimazu house as 'a difficult opponent to conquer.

' The fact of having inflicted a fatal wound on the Tokugawa Four Heavenly Kings' Ii Naomasa made the Tokugawa side foresee the cost of a Satsuma conquest.

The abnormal fierceness of the retreat combat substantially raised the Shimazu side's bargaining power in the subsequent Shimazu-Tokugawa negotiations.

A rare case in which the judgment of Yoshihiro as an individual warrior determined the fate of the whole Shimazu house.

The Satsuma domain of 770,000 koku that survived Sekigahara continued through the Edo period as one of the largest presences among tozama daimyō.

The Edo bakufu was always wary of the Satsuma domain and continuously applied economic pressure — sankin-kōtai burdens, Kiso River flood-control works — but the domain's substance was not diminished.

This accumulation exploded in the Bakumatsu. In the Boshin War of 1868, the Satsuma domain, centered on Saigō Takamori (this site's id 21) and Ōkubo Toshimichi (this site's id 26), became the core of the Meiji Restoration.

Counting from Yoshihiro's retreat combat of 1600, 268 years later, the survival of the Shimazu house directly connected to the birth of modern Japan.