The Battle of Sacheon: In 1598, 7,000 Satsuma Troops Repelled a Ming Army of Tens of Thousands

On October 1, 1598 (the first of the tenth month of Keichō 3), at Sacheon in southern Korea (modern Sacheon, Gyeongsangnam Province, South Korea).

The Sacheon New Castle held by roughly 7,000 Satsuma troops under Shimazu Yoshihiro was attacked by a Ming army of some 20,000 under Dong Yiyuan, plus several thousand Korean troops.

Yoshihiro was sixty-three. It was combat in the latter part of the Korean campaign, at a time when Toyotomi Hideyoshi had already died (August 18, at Ōsaka) and withdrawal had been decided.

Sacheon was a strategic point on the transportation route linking Suncheon Japanese Castle (Konishi Yukinaga) in southern Korea with the various daimyō at Busan, and the Shimazu army had built a fortified new castle there.

Facing the sea in position, it enabled seaborne return home as an escape route.

Yoshihiro, anticipating Ming attack, concentrated his troops and prepared for a small-elite siege defense.

The force of about 7,000 was medium-sized among Japanese armies in southern Korea at the time.

In the morning of October 1, the Ming army began attack on the outer wall of the new castle.

It was a large-scale attack combining charges on the walls with bombardment by muskets and cannon.

Yoshihiro fought back with concentrated deployment of gunpowder and gun-troop position defense, and repelled the Ming charges.

In the afternoon, the Shimazu army opened the castle gate and counterattacked, pursuing the confused Ming army.

In half a day of combat, the Ming army produced several thousand dead, and Dong Yiyuan withdrew.

The Shimazu army's dead are transmitted at some tens to a hundred.

After this combat, the designation 'Guǐ Shímànzǐ' (Devil Shimazu) is said to have arisen from the Ming army, according to Shimazu-family sources from the Edo period on.

But it is difficult to directly confirm this designation in contemporary Ming-side primary sources, and the possibility is high that it took shape within Japanese-side veneration.

Beyond the truth of the traditional designation, the fact itself that Yoshihiro won at Sacheon against tens of thousands of enemies with 7,000 is corroborated in multiple sources.

It became one of the largest-scale combats recorded as a Japanese-side victory throughout the Korean campaign.