水淹七军
This is a story from Three Kingdoms.
Cao Cao appointed Yu Jin as the chief commander in charge of the southern expedition, together with Pang De in the vanguard(前锋) . They led seven armies to rescue Fancheng City. When Guan Yu of Shu learned this, he led his army to take them on. Guan and Pang fought over one hundred rounds with neither gaining an advantage. The fight continued on the second day without an exchange of words. After another 50 rounds, Pang rode his horse to flee and Guan rode after him. Pang shot an arrow at Guan who was unable to dodge(躲避) it. The wounded Guan went back to his camp for recuperation(恢复) . Ten days later, Guan's wound got healed. Guan Yu learned from Guan Ping that Cao Cao's army had moved to the north of the city. Guan Yu went to a nearby hilltop to look at the terrain. He saw the enemy's troops in the northern mountain valley, also, he noticed that the Xiangjiang River was unusually swift. He hit on the idea of flooding the seven armies. He ordered his army to get boats and rainwear ready. He had his men dam up several points in the river so as to flood Cao Cao's army. Pang De talked with his generals of moving out of the valley onto higher ground the next day.
That night, wind blew fiercely and rain came down heavily. Pang De, sitting in his tent, heard the restless movements of the horses and the sound of battle drums. Alarmed, he went outside to look. From all sides, floodwaters were rushing in, the seven armies, thrown into a panic, had already lost untold numbers in the tide. The water reached a depth of over three meters. With their soldiers, Yu Jin and Pang De climbed to higher ground. Guan Yu urged his forces to strike. Yu Jin and Pang De's armies, seeing no way out, surrendered. Pang De, who had gotten hold of a boat, tried to escape westward. The boat, however, was knocked down by Zhou Cang's raft and Pang De was captured alive.