Siege of Takamatsu
In the 1582 Siege of Takamatsu, Toyotomi Hideyoshi laid siege to Takamatsu Castle, which was controlled by the Mōri clan. He diverted a nearby river with dikes to surround and flood the castle. He also constructed towers on barges from which his gunmen could keep up a constant rate of fire and be unhindered themselves by the flooding.
As the battle grew more intense, the Takamatsu garrison received reinforcements from Mōri Terumoto, who brought an army six times larger than Hideyoshi's. Hideyoshi then requested aid from Oda Nobunaga. In response, Nobunaga mobilized six of his commanders, which he planned to lead the resultant army.
Hideyoshi soon learned of the Incident at Honnōji and the death of Nobunaga, which encouraged him to end the siege. Shimizu Muneharu, the castle's commander, was forced to commit suicide in a boat on the artificial lake created by the flooding, in full view of both sides.
