Part of the Taira-Minamoto wars the Gempei War in Japan lasted from 1180 until 1185. It was fought between the Taira clan, which was losing influence, and the Minamoto clan, which hoped to replace the Taira clan. It resulted in a victory for the Minamoto clan, and the emergence of Minamoto Yoritomo as the shogun (“general who subdues barbarians”) in 1192. The name Gempei came from a contraction of the names Genji and Heike, which were the kanji characters for “Minamoto” and “Taira.”
The Minamoto clan previously tried to topple the Taira, in the Hogen War of 1156 and the Heiji War of 1159–1160. In the first the Minamoto had supported a rival claimant to the throne and lost. In the second, they staged a surprise coup but were decisively defeated by the Taira.
In the Gempei War in 1180, as the Minamoto were gaining strength, the Taira attacked first. Taira supporters surprised Prince Mochihito, the claimant to the imperial throne and favored by the Minamotos, at a temple near Kyoto. Deciding that it was impossible to defend the temple, they fled across the Uji River, removing the planks on the bridge across the river.
However the Taira forces were able to ford the river and cornered their opponents. Yorimasa, injured by an arrow, commited ritual suicide by seppuku, disemboweling himself—the first known time this had taken place. Soon afterward Prince Mochihito was killed.
The Taira then capitalized on their victory at Uji by attacking Nara, the base of warrior monks opposed to them. Although the monks were in strong defensive positions, the Taira used their cavalry to great advantage, capturing and then destroying all the temples in Nara except Enryakuji. It is reported that 3,500 people were killed during the sacking of Nara.
Following this, Minamoto Yoritomo, assisted by men from the Miura clan, tried to regroup, but the Taira launched a quick attack and routed them at the Battle of Ishibashiyama. Soon afterward Minamoto Yoritomo rallied his troops and turned on the Taira. At the Battle of Fujigawa, it was said that when a flock of birds surprised the Taira, they fled in panic.
In 1181 Minamoto Yukiie attempted to attack Taira Tomomori, whose army was encamped along the Sunomata River. The Minamoto were driven back with heavy losses and retreated across the Yahagigawa River, pursued by the Taira. When Tomomori fell ill, the Taira pulled back. After a lull in fighting, in 1183 Taira Koremori launched an attack on a Minamoto castle at Hiuchiyama.
The fortifications were capable of withstanding a siege, but a traitor from within the castle tied a message to an arrow and shot it into the Taira camp, showing how they could breach a dam around the castle. The Taira attacked and the Minamoto forces fled. Although the Taira won the first part of the war, their leadership had grown arrogant and annoyed smaller clans, who were won over by the Minamoto.
Making the most of this victory Taira Koremori pursued the Minamoto to Kurihara (also known as the Battle of Tonamiyama). Minamoto Yoshinaka cunningly split his forces and ambushed the Taira as they went through a mountain pass. By disguising the strengths of the three wings of the army, Minamoto Yoshinaka surrounded the Taira. It was the turning point in the war, as many of the Taira forces were killed, and they were forced to withdraw their garrison from Kyoto and fled along with their ally Emperor Antoku to Shikoku.
On November 17, 1183, Minamoto Yoshinaka sent his ships against the Taira in the Battle of Mizushima— the first naval battle of the Gempei War. The Taira were victorious, but soon afterward a Minamoto army captured the castle of Fukuryuji, which had been held by a supporter of the Taira. The Minamoto then tried to press their military advantages by engaging the Taira in another battle at Muroyama but were defeated.
A struggle suddenly broke out with Minamoto Yoshinaka trying to wrest power from his cousins Minamoto Yoritomo and Minamoto Yoshitsune. Yoshinaka captured the Hojoji Palace in Kyoto, took Emperor Go-Shirakawa prisoner, and named himself shogun. Soon after the rest of the clan surrounded him, forcing him to choose between inevitable defeat in battle or flight. He chose the latter and his men fled across the Uji River, but Yoshitsune’s cavalry forded the river and in the second Battle of Uji, Yoshinaka was defeated. He made a final stand at Awazu and was killed by an arrow.
With Yoshinaka dead the Minamoto concentrated on the final defeat of the Taira. At Ichi-no-Tani, the Minamoto attacked a Taira fortress near modern-day Kobe. The battle became legend in Japanese folklore, with many famous warriors engaging in combat. Eventually the 16-year-old Taira leader, Atsumori, was killed, later dramatized in plays and works of fiction. The Minamoto then followed up their victory by attacking and defeating Taira allies at the Battle of Kojima.
The last two battles of the war were both at sea. At Yashima on March 22, 1185, Minamoto Yoshitsune launched a surprise attack on the Taira. Bluffing that he had far more men, Yoshitsune sent the Taira into premature retreat, abandoning their fortifications at Shikoku. Most of the Taira fleet escaped, but at the Battle of Dannoura, off the southern tip of Honshu island, on April 25, 1185, the Minamoto attacked their outnumbered opponents—it was estimated that the Minamoto used 850 ships against their opponents’ 500.
At a crucial time a Taira ally switched sides and told the Minamoto which ship the six-year-old Emperor Antoku was hiding on. The Minamoto attacked it, killing the emperor along with his grandmother, a member of the Taira clan.
With the Taira totally defeated, Minamoto Yoritomo, the older half brother of Yoshitsune, became the first shogun in Japanese history and established what became the Kamakura Shogunate. It was not long before Yoshitsune, Yoshiie, and Yoshinaka were killed by orders of Yoritomo or were forced to commit suicide. The system of rule by the shogun continued, in several different forms, until the Meiji Restoration of 1868.