Takamatsu Castle (Bitchu Province)

Takamatsu Castle
高松城
Okayama, Okayama Prefecture, Japan
An excavated portion of the dike and embankment base constructed by Toyotomi Hideyoshi in his 1582 siege of the castle.
Type	Azuchi-Momoyama castle
Site information
Controlled by	Ishikawa clan (until 1575), Mōri clan (1575–1582), Toyotomi Hideyoshi (1582–1598), Hanabusa clan (c. 1598 – mid-17th century)
Condition	Archaeological site and designated national historical site; signs of Hideyoshi's siege equipment and dikes remain, but remnants of the castle do not.
Site history
Built	late 16th century
Built by	Mimura clan
In use	late 16th to mid-17th centuries
Materials	Wood, stone, plaster
Battles/wars	Siege of Takamatsu (1582)
Garrison information
Past commanders	Shimizu Muneharu (c. 1575–1582)

Takamatsu Castle (高松城^?, Takamatsu-jō) of Bitchū Province was a Japanese castle located in what is today the city of Okayama in Okayama Prefecture. Like most Japanese castles, it was built in the late 16th century, during the Azuchi–Momoyama period of Japanese history.

The castle, of the hirajō (plains castle) type, was built very close to sea level, on somewhat marshy ground, which formed something of a natural moat; this distinguishes it from the more stereotypical image of a yamashiro (mountain castle), built atop a hill. It was originally built by the Mimura family, and controlled by their vassals, the Ishikawa family. Both families were eliminated as significant powers by the Mōri clan, who seized Takamatsu, and all of Bitchu province, in 1575. The Mōri entrusted the castle to their vassal Shimizu Muneharu. Shimizu was closely related to the Ishikawa family, and it's possible that he was already lord of Takamatsu shortly before the Mōri attacked, turning to their side upon the defeat of the Ishikawa, in order to maintain his own prestige and power, along with the castle.

In 1582, the castle was besieged by Toyotomi Hideyoshi. After a month or two of siege, Hideyoshi built dikes to divert a nearby river, at the suggestion of his strategist Kuroda Kanbei, and flooded the castle, leading to a quick surrender on the part of Shimizu. The ease with which this was accomplished was brought about in great part due to the marshy condition of the area, and the timing of the siege: the rainy season (tsuyu) exacerbated the flooding to such an extent that it is easy to imagine the fortress truly being literally flooded, and surrender becoming quite inevitable.