The Ōuetsu Reppan Dōmei (Northern Domains Alliance)

Overview

The Ōuetsu Reppan Dōmei was an alliance formed in 1868 (Keiō 4), in the midst of the Boshin War, by the domains of Ōu (northeastern Japan), led by Sendai and Yonezawa, joined by domains of Hokuetsu (northern Echigo). Its founding date is given as the 6th day of the 5th month of Keiō 4, when the Hokuetsu domains joined, but accounts differ, and another view takes the 3rd day of the 5th month, when twenty-five domains signed the covenant in Sendai. The membership is given as thirty-one domains in total, the Ōu domains joined by six Hokuetsu domains.

The alliance received Prince Kōgen of Rinnō-ji (later Prince Kitashirakawa Yoshihisa) as its nominal leader. But after the allied forces were defeated at Shirakawa-guchi and elsewhere, its cohesion collapsed and domains surrendered one after another between the 7th and 9th months. The alliance did not surrender as a body; each domain surrendered individually, which characterizes the way it came apart.

The Shiroishi Conference

The starting point of the alliance was the Shiroishi conference at Shiroishi Castle. On the 11th day of the intercalary 4th month, fourteen Ōu domains met at Shiroishi Castle and submitted to the Governor-General's headquarters a petition asking for lenient treatment of Aizu, which was rejected; on the 23rd of the intercalary 4th month, eleven further domains joined and signed the Shiroishi covenant.

Formation and Expansion into Hokuetsu

On the 3rd day of the 5th month, twenty-five domains signed the covenant in Sendai. Treatment differs depending on whether the founding is dated to the 3rd or the 6th.

Domains of Hokuetsu then joined. Nagaoka joined on the 4th of the 5th month, and five other Hokuetsu domains, including Shibata, joined on the 6th. In the end, six Hokuetsu domains joined the Ōu domains, making thirty-one in all. The core of the alliance was formed by Sendai and Yonezawa.

The Nominal Leader and the Kōgi-fu

Prince Kōgen of Rinnō-ji was received as the alliance's nominal leader. On the 16th of the 6th month it was settled that he would take up only the post of leader, and on the 12th of the 7th month he entered Shiroishi Castle and attended the council of domains.

As the alliance's policy body, the Kōgi-fu (Ōuetsu Kōgi-fu) was set up at Shiroishi.

Battles and Collapse

The allied forces were defeated at Shirakawa-guchi, Tanagura, Iwakitaira and elsewhere. The alliance then fell apart rapidly.

Miharu submitted to the new government's forces on the 26th of the 7th month, and Nihonmatsu Castle fell on the 29th. Sōma-Nakamura surrendered on the 6th of the 8th month. In the 9th month, Yonezawa surrendered on the 4th and Sendai on the 12th. Morioka, Aizu and Shōnai surrendered between the middle and end of the 9th month (Aizu's Wakamatsu Castle was surrendered on the 22nd). The nominal leader, Prince Kōgen, surrendered on the 18th.

In Hokuetsu, Nagaoka Castle fell on the 19th of the 5th month, was retaken on the 24th of the 7th month, and fell again on the 29th. The alliance never surrendered as a whole; the fact that domains surrendered individually shows that it was not monolithic, either militarily or politically.

Castles Connected with the Alliance

The main castles connected with the alliance include Sendai, Yonezawa, Shirakawa-Komine, Nagaoka and Aizu-Wakamatsu.