台城跡
水島城とも呼ばれる台城は、菊池一族が隈府の城下町を守るために築いた十数か所の中世城郭のひとつだった。菊池氏の居城から西に5キロほど離れた台地の端に位置し、西に面していたため、菊池川のはるか下流を一望することができた。この戦略的な立地に加え、丘の真下には内田川が流れていたため、台城の侵攻は困難を極めた。
城の歴史の中で最も有名な戦いは、1375年に菊池氏が武家主導の中央政権・足利幕府と戦ったときに起こった。ほんの数年前まで九州全土を支配していた菊池氏は、足利軍の将軍・今川了俊（1326-1420）の手によって次々と挫折し、先祖代々の土地に押し戻されていた。
菊池の抵抗に終止符を打つため、了俊は水島の戦いに数万の兵を引き連れたが、当時まだ12歳だった新任の当主、菊池武朝（1363-1407）の率いる約2,000人の軍勢に敗れた。武朝の勝利は了俊の菊池征伐を遅らせたが、6年後のその目的はついに果たされた。
Site of Utena Fort
Utena Fort, also known as Mizushima Fort, was one of more than a dozen medieval strongholds built by the Kikuchi clan to defend the castle town of Waifu. The fortress faced west on the edge of a plateau around 5 kilometers west of the clan’s castle and had an unimpeded view far downstream along the Kikuchi River. This strategic location, along with the additional protection provided by the Uchida River directly beneath the hill, made Utena Fort extremely difficult to invade.
The most famous battle in the fort’s history took place in 1375, when the Kikuchi clan was fighting against the Ashikaga shogunate, the warrior-led central government. The Kikuchi, who only a few years prior had controlled all of Kyushu, had been pushed back to their ancestral lands after successive setbacks at the hands of the Ashikaga general Imagawa Ryoshun (1326–1420).
Seeking to end Kikuchi resistance for good, Ryoshun brought tens of thousands of warriors to the Battle of Mizushima, but was defeated by a force of 2,000 under Kikuchi Taketomo (1363–1407), the newly appointed clan leader who was only 12 years old at the time. Taketomo’s victory delayed Ryoshun’s conquest of Kikuchi, which he nonetheless completed six years later.
