The Hara Castle Siege: An Uprising of 37,000 That Endured a Bakufu Army of 120,000 for Three Months

On December 4, 1637, at Hara Castle in Hizen Province (modern Minami-Arima-chō, Minami-Shimabara City, Nagasaki Prefecture).

The uprising force of 37,000 led by Amakusa Shirō entered an abandoned castle built at the southern tip of the Shimabara Peninsula.

It had once been the castle of the Arima and had been abandoned by the 1615 one-castle-per-province edict.

Its position, built on cliffs jutting into the sea, was suited for siege defense, and Shirō and the others made this their final base.

For the next three months and more, the largest-scale religious-war siege in Japanese history began.

The initial response of the bakufu had tried to settle it by response of Kyūshū daimyō, but the resistance of the uprising force was stronger than expected, and the scale expanded.

In January 1638, the bakufu dispatched the elder Matsudaira Nobutsuna as commander-in-chief and finally strengthened the mobilized force to more than 120,000.

Against an uprising force of 37,000 (of which around 15,000 combatants), a force four times as large.

This scale was of the largest class for internal war in the Edo period, and became the largest mobilization since the Ōsaka Summer Campaign of 1615.

A rare case in which the Edo bakufu, continuing 260 years, became militarily serious in peacetime.

In February 1638, the bakufu asked the Dutch factory at Hirado, and had the ship 'de Rijp' bombard Hara Castle.

A strange structure arose in which the Protestant nation the Netherlands bombarded the Catholic-affiliated Kirishitan uprising from the bakufu side.

The Dutch intent was cooperation to secure the trade relationship with the bakufu.

This bombardment greatly reduced the morale of the besieged side. It became a scene symbolizing the peculiar nature of the Shimabara Rebellion as a moment in which religious conflict and international politics strangely intersected.

By three months of siege, the uprising force's food had run out, and they had suffered many casualties.

On February 28, 1638, the bakufu army began the total attack. By the twenty-ninth, Hara Castle fell, and nearly all of the uprising force including Shirō were killed.

Those who survived are said to have been only some hundreds. Shirō's head was exposed in front of Dejima at Nagasaki.

He was around seventeen. A rare end for a teenage leader in Japanese history. The four-month siege war was a fierce combat that also produced around 10,000 casualties for the bakufu army.