Battle of Yamazaki

The Battle of Yamazaki (山崎の戦い) was fought in 1582 in Yamazaki, Japan, located in current day Kyoto Prefecture. This battle is sometimes referred to as the Battle of Mt. Tennō (天王山の戦い Tennō-zan no tatakai).

In the Honnō-ji Incident Akechi Mitsuhide, a retainer of Oda Nobunaga, attacked Nobunaga as he rested in Honnō-ji, and forced him to commit seppuku. Mitsuhide then took over Nobunaga's power and authority around the Kyoto area. Thirteen days later, Toyotomi Hideyoshi met Mitsuhide at Yamazaki and defeated him, avenging his lord (Nobunaga) and taking Nobunaga's authority and power for himself.

Preparations for Battle
When Nobunaga died, Hideyoshi was busy fighting the Mōri clan. After betraying and defeating Nobunaga at Honnō-ji, Mitsuhide sent a letter to the Mōri. The letter contained a request for an alliance to crush Hideyoshi, but the letter's messenger was captured by Hideyoshi's forces and the plot was revealed.

Upon hearing news that Nobunaga had been killed, and that Akechi Mitsuhide had taken command of his possessions, Toyotomi Hideyoshi immediately negotiated a peace treaty with the Mōri, remaining careful to keep Nobunaga's death a secret. Once the treaty was secured, he then led his troops on a forced march towards Kyoto, averaging 30 to 40 km a day.

Akechi Mitsuhide controlled two castles (Shōryūji and Yodo) in the Yamazaki region. Due to his lack of men for the impending battle with Hideyoshi, he attempted to win the hearts of the people in that region in order to gain more troops. However, his appeals to Hosokawa Fujitaka were fruitless, and so he was unable to add significant strength to his forces.

Less than two weeks after Mitsuhide's betrayal, Hideyoshi's army finally arrived and attacked Mitsuhide's inferior forces at Yamazaki. Learning of the size of Hideyoshi's army and not wanting to be caught inside a castle with his force divided, Mitsuhide resolved to prepare for battle somewhere to the south. Due to its position between a river and a mountain, Yamazaki provided Mitsuhide with choke points that could ease the number of enemies his forces would have to face at any one time.

Meanwhile, Hideyoshi decided that a wooded area called Tennōzan, just outside the town of Yamazaki, was key to strategic control of the road to Kyoto. He sent a detachment under Nakagawa Kiyohide to secure this area, while he led the majority of the army to Yamazaki himself. His forces took over the mountain and gained a significant advantage.

Mitsuhide arranged his army behind a small river (the Enmyōji-gawa), which provided an excellent defensive position. That night, Hideyoshi's men sent a number of ninja into the Mitsuhide camp, setting fire to buildings and generally causing fear and confusion.

The battle
On the following morning, the main fighting began as Hideyoshi's men began to form up along the opposite shore of the Enmyōji-gawa from the enemy, and a portion of Mitsuhide's men crossed the river, seeking to make their way up the wooded Tennōzan hill. They were driven back by arquebus fire, and so Hideyoshi felt confident enough to launch the right wing of his forces across the river, and into Mitsuhide's front lines. They made some progress, and were soon joined by the left wing, with support from atop Tennōzan. The majority of Mitsuhide's men fled, with the exception of the 200 men under Mimaki Kaneaki, who charged and were destroyed by Hideyoshi's larger force.

Soon, panic set in among the Mitsuhide army, and Hideyoshi's army chased them back to Shōryūji. Mitsuhide himself fled much further, to the town of Ogurusu, where he was captured by bandits and killed. Mitsuhide is rumored to have been killed by a peasant warrior with a bamboo spear by the name of Nakamura; however, there were also rumors that he was not killed, but rather started a new life as a priest called Tenkai. Hideyoshi used this victory as a stepping-stone to gain control over Nobunaga's former territories and eventually all of Japan.

In popular culture
The Battle of Yamazaki is the final stage of Akechi Mitsuhide and the first stage of Toyotomi Hideyoshi in Samurai Warriors 2.

The battle is also the basis for the Sonny Chiba martial arts film Shogun Ninja.