Emperor Shirakawa II had abdicated on September 5, 1158, in favor of his son, but his abdication had implied no cession of political or other powers to his successor.
He has attempted to continue the long-customary practice of ruling in actuality from a cloistered position, but real power has begun to be wielded by the heads of the Taira and Minamoto clans, the leading samurai families.
The simmering feud between the two clans, long suspicious of one another, has escalated as jealousy and friction increases and the Minamotos plot to rid themselves of their rivals at the imperial court.
In late 1159, Taira no Kiyomori, head of the Taira clan and supporter of Emperor Nijō, had left Kyōto with his family on a personal pilgrimage.
This has left his enemies, Fujiwara no Nobuyori and the Minamoto clan, a perfect opportunity to effect an uprising.
Fujiwara no Nobuyori and Minamoto no Yoshitomo see an opportunity to effect changes they seek in the government in early January 1160.
With a force of roughly five hundred men, they attack in the night, kidnapping former emperor Emperor Go-Shirakawa, and setting fire to the Palace.
They also abduct and imprison the current emperor, Emperor Nijō, who supports their enemies, the Taira clan and Fujiwara no Michinori.
They next attack the manor house of Michinori, setting it too aflame and killing all those inside, with the exception of Michinori himself, who is captured later and decapitated.
Nobuyori forces Emperor Nijō to name him imperial chancellor, completing one of the first important steps towards gaining power over his rivals.
However, Taira no Kiyomori returns soon afterwards, with his son Taira no Shigemori and a small force.
The Minamoto, reinforced with men from Kamakura led by Yoshitomo's eldest son Minamoto no Yoshihira, are the larger force but are unprepared, and hesitate at Kiyomori's return.
The Taira are thus allowed to return to their family's mansion in the Rokuhara district, where they plan tactics and strategies, and gain many more warriors.
At the end of January, the Taira smuggle the Emperor Nijō and his empress consort out of the Sanjō Palace and into the Rokuhara mansion, disguised as a lady in waiting.
Meanwhile, the Taira also help the former emperor Emperor Go-Shirakawa escape from the Minamoto as well.
