The Hogen and Heiji Disturbances
Backdrop: Japanese politics in the 12th Century
The Hogen Disturbance of 1156 was the first of two brief armed conflicts that traditionally are viewed as foreshadowing the Genpei War of 1180-85. The result of internal divisions within the imperial family and the Regent's House of the Fujiwara clan, the Hogen Disturbance marked the beginning of a time of turmoil that was to last until the political settlement that followed Genpei.
By the 12th Century the Japanese emperors had began to reassert themselves against the Fujiwara clan, who had previously dominated government. Using the office of retired emperor and the administrative organization attached to it, Emperors Go-Sanjo and Shirakawa succeeded in making the head of the imperial family the effective ruler of Japan again. Power now rested in the title of senior retired emperor. But it also created new tensions within the imperial family. The power wielded by the senior retired emperor in family and political affairs was resented by other members. In 1129 Shirakawa died, allowing his grandson Toba to become senior retired emperor. Toba was determined to control the succession and keep power in his chosen line.
Toba had first retired in 1123 in favor of Sutoku, supposedly his son. However, rumors flew that Sutoku was in fact Toba's uncle, the product of an affair between Shirakawa and one of Toba's consorts. This may explain the bad blood between Toba and Sutoku, nevertheless the latter remained on the throne until 1141. That year, Sutoku was retired in favor of Konoe, the son of Toba's favorite consort (Fujiwara Tokushi, later known as Bifukumon'in). In 1155 Konoe died at 16, always of frail health, and Toba was heartbroken. A new successor would have to appointed, and Sutoku campaigned heavily in favor of his own son. But Toba appointed another of his sons, Go-Shirakawa, as emperor with the understanding that his reign was a stopgap measure. Behind the scenes, Bifukumon'in had brought about this solution intending for the throne to pass to Go-Shirakawa's young son (the future Emperor Nijo), her favorite. The following year Toba fell ill and it was soon clear he was dying. Sutoku saw his chance to become senior retired emperor and began mustering military forces to contest the issue
Tadamichi and Yorinaga
Adding fuel to the fire was a rivalry between brothers in the Fujiwara Regent's House. In 1122 the former head of the family, Fujiwara Tadazane, broke with Retired Emperor Shirakawa, replaced with his eldest son Tadamichi, and retired. Tadazane remained active by working with Toba. When Toba came to power in 1129 Tadazane returned to court and continued to undermine Tadamichi by working with his younger son Yorinaga. The two entered an intense rivalry over the following decades. In 1150 Tadazane attempted to have Tadamichi deposed in favor of Yorinaga. But the elder son, working with Bifukumon'in, managed to stay in power though he lost headship of the family.
The death of Emperor Konoe in 1155 triggered the political collapse of Yorinaga as his (adopted) daughter's marriage to Konoe was his only real tie to power. This, combined with accusations that Yorinaga had cursed the young emperor, led to the forced retirement of the Fujiwara pretender. His father followed soon after due to a decline in his own fortunes. In Sutoku the two men found the perfect ally and they formed an alliance with the understanding that Yorinaga would become regent and chancellor once Sutoku became senior retired emperor.
The Genji and the Heishi
Sutoku gathered disaffected leaders of both of the major clans of warrior nobles to his cause. Chief among them was Minamoto Tameyoshi and Taira Tadamasa. Tameyoshi was technically the head of the Minamoto clan (or Genji), but not even his own family recognized his authority. Most of the Minamoto leading vassals followed Tameyoshi's eldest son Yoshitomo and joined Go-Shirakawa. Tadamasa was the uncle of Taira Kiyomori, current head of the Taira clan(or Heishi).
When the previously dominant Genji began to fracture early in the century an obscure branch family of the Taira took their place. These Ise Taira went on to form a patron-client relationship with the senior retired emperors similar to that of the Minamoto with the Regent's House of the Fujiwara. Toba, before his death, had foreseen that an armed clash would be coming and ordered Kiyomori and Yoshitomo to mobilize.
As a result, when Toba died on the lunar calendar date of 1156/7/2 his forces, in support of Go-Shirakawa, were already active near the junction of the Kamo and Katsura rivers and Takamatsu Palace. Sutoku became concerned and started calling his supporters to his residence at Shirakawa Palace. While most of his men reached Shirakawa, the Yamato Minamoto called by Tameyoshi were taken prisoner by the loyalists and a force from Kofukuji (the Fujiwara clan temple) never arrived. On the 11th day Sutoku's men had finished gathering and began to debate on what to do next.
Night Attack on Shirakawa Palace
The decision was made to wait for Kofukuji's reinforcements to arrive, but that night Go-Shirakawa's men attacked. Supposedly led by Yoshitomo and Kiyomori in person with around 600 men the loyalists rode a mile and a quarter to the opposing palace in northeastern Kyoto and overwhelmed the defense in a matter of hours. Later tradition, found the war tale “Hogen monogatari”, ascribes superhuman feats of arms to Minamoto Tametomo (Yoshitomo's younger brother) and credits him for single-handedly holding off the attack until Yoshitomo resorts to setting fire to the palace.
During the battle Sutoku fled to the temple of Ninnaji were he was arrested. The retired emperor was sentenced to exile in Sanuki in Shikoku and kept there for the rest of his life. Fujiwara Tadazane permanently retired from politics. Fujiwara Yorinaga was shot with an arrow and died of his wounds in days. Though most of the losing side's supporters were dealt with the normal way with exile, seventeen warrior nobles were executed. The first time such had happened in 350 years.
The victorious Kiyomori and Yoshitomo were given rather meager rewards, and both wanted more. Kiyomori, with his family history of direct service to the throne, came out the better. Tensions between the former allies and the rise of Go-Shirakawa adviser Fujiwara Michinori would contribute to the outbreak of the Heiji Disturbance only three years later.
The Rise of Shinzei
Victory for Go-Shirakawa in the Hogen Disturbance in 1156 did not long bring peace to the capital city of Kyoto. Envy and resentment divided the camp of the winners and caused a falling-out which led to the fighting.
Go-Shirakawa, for the first two years that followed Hogen, enjoyed sole imperial power. His chief advisor was Fujiwara Michinori, better known by the Buddhist name Shinzei. Shinzei's wife had been the emperor's wet nurse and for that reason he enjoyed great power out of proportion to his actual low rank. In 1158 the Go-Shirakawa retired, becoming senior retired emperor. The throne was now taken by his son Nijo, following the agreement of 1155 under which Go-Shirakawa had first ascended. Nijo, despite his youth (being only 15), was intelligent and quick-witted and intended to rule as well as reign.
Therefore he ignored his father and carried on affairs on his own. The young emperor was supported by Bifukumon'in (the consort of Toba who originally backed him) and a cadre of officials. Chief among these were two Fujiwara, Tsunemune and Korekata. Military power was held by Minamoto Mitsuyasu and Yorimasa. Meanwhile in the retired emperor's camp Shinzei had become the dominant personality, with only the warrior noble Taira Kiyomori coming close to rivaling him. Together the two men carefully guarded their hold on power.
When the retired emperor began advancing a new courtier through the ranks, Fujiwara Nobuyori, Shinzei acted quickly to block him. The older man began to belittle Nobuyori in court every chance he got. The struggle continued until Go-Shirakawa denied Shinzei's would-be successor appointment to a plum title that was normally treated as a springboard into the higher offices of government. Nobuyori pleaded illness and vanished into seclusion. Meanwhile Minamoto Yoshitomo, now head of the Minamoto clan, was meeting his own difficulties.
Yoshitomo plots with Nobuyori
Frustrated with the lowly office he had received as a reward for his service during the Hogen Disturbance, Yoshitomo attempted to “fix” that problem through Shinzei. A marriage alliance was suggested between the Minamoto head's daughter and the Fujiwara courtier's son. The offer was rejected for Kiyomori had already made such an alliance. He was determined to keep Yoshitomo from advancing too far.
The two disgruntled men found in each other natural allies and they began to plan on to best remedy what they felt was a wrongful denial of position. In late December 1159-early January 1160 Taira Kiyomori announced he would be embarking on a pilgrimage to the Kumano Shrine in modern Mie Prefecture. Once he left with a small body of retainers and his eldest son, Shigemori, Nobuyori and Yoshitomo saw their chance.
They waited five days, knowing that would be the time it would take to reach Kumano, and sprung a coup. On 1159/12/9 of the lunar calendar a small band of largely Minamoto warriors attacked Go-Shirakawa's residence at Sanjo Palace. The senior retired emperor was taken hostage and the palace burned along with Shinzei's nearby home. The conspirators took their hostage to the Greater Imperial Palace and placed him and Emperor Nijo under house arrest. Nijo's supporters, hoping to use this opportunity to strengthen the emperor, agreed to support the coup.
On 1159/12/10 Fujiwara Nobuyori took control of the government. He dismissed Shinzei, Kiyomori, and their supporters from their posts. For himself he secured high office and a governorship for Yoshitomo. A few days later Shinzei himself, who disappeared during the initial coup, was found in Nara and executed. In triumph, Nobuyori had his enemy decapitated and the head brought back to Kyoto for display in public like that of a common criminal.
News of what had happened reached Kiyomori quickly. At first he reacted with some hesitancy, but eventually decided to return to the capital. Picking up a total of 400 men along the way, the Taira head made it to his home at Rokuhara in the southeastern Kyoto on 1159/12/17. He submitted to the new government soon after and prepared to bide his time. Meanwhile Nobuyori grew arrogant and his supporters began to fall away. On 1159/12/26 Fujiwara Tsunemune and Korekata advised Emperor Nijo to escape and head for Rokuhara. Disguised as a lady-in-waiting, the emperor successfully made his way to Kiyomori and condemned the coup-plotters as rebels to the empire. Go-Shirakawa also escaped, through unknown means, to Ninnaji Temple.
The Samurai Archives Wiki is an excellent resource for Pre-Modern Japanese history.
Kiyomori smashes Yoshitomo
The next day Taira Shigemori and his uncle Yorimori led their retainers to the Greater Imperial Palace. A fierce fight ensued between the opposing cavalry which ended when Shigemori could successfully lure the Minamoto out of the palace grounds, allowing his own warriors to occupy it. Yoshitomo decided to head straight to Rokuhara, intending to take down Kiyomori. The head of the Taira clan was waiting for them and another fight ensued. The “rebels” were crushed when Minamoto Yorimasa failed to show up. The survivors fled eastwards to their powerbase.
Nobuyori was found near Rokuhara on the bed of the Kamo River heading for Ninnaji to beg forgiveness. Instead he was executed. Yoshitomo escaped as far as the region of modern Shiga and western Aichi Prefectures before being betrayed and killed by his own retainers. Other Minamoto suffered the same fate including Yoshitomo's older sons, or were exiled. Among the latter was the future first Shogun, Minamoto Yoritomo. Supposedly spared execution by the pity and intervention of Kiyomori's stepmother.
For the next twenty-five years the Taira would enjoy unprecedented political ascendancy in a situation that would endure until the Genpei War.