Narrow Road To The Deep North 12

The next morning, while Marume and Washizu were going up in flames, Nobunaga led a handful of men out of his castle and headed in the direction of Imagawa's army. Along the way he collected enough ashigaru and samurai to make an attack still foolish. Despite the odds, the priests at the Atsuta Shrine that he stopped to pray at commented on how calm he appeared.
Nobunaga's scouts had reported that Yoshimoto was resting in the narrow gorge of Dengaku-hazama, celebrating his victories with sake, and viewing the heads taken at Marume and Washizu. It was an ideal place for a surprise attack.
Nobunaga moved up towards Yoshimoto's encampment, and set up a position some distance away. An array of sashimono battle flags were hoisted up from behind a hill, on dummy troops made of straw and spare helmets, to give the impression of a large host, while Nabunaga’s real army hurriedly marched around the Imagawa. 
Broiling heat gave way to a terrific summer thunderstorm. The torrential downpour forced the Imagawa samurai to take shelter, and enabled Nobunaga to quietly sneak up closer to Yoshitomo's position. When the rain stopped, he launched a swift attack, charging down the gorge, staggering the entire Imagawa army into a daze. 
So sudden and ferocious was the ambush that Yoshimoto initially assumed a brawl had broken out among his men. The correction came suddenly, with two of Nobunaga’s samurai. One aimed a spear, which Yoshimoto deflected with his sword, but the second swung his blade and took off the Imagawa's head. His army fled, utterly defeated. 
Nobunaga's inconceivably stunning victory at Dengaku-hazama changed the course of Japanese history. It brought him national fame as a strategist, and removed a wolf from his back door. A year later Nobunaga forged an alliance with Toyotomi Hideyoshi and Tokugawa Ieyasu, and begin building a foundation that would lead to the unity of Japan.