A few events illustrative of the conditions we have described may here be cited. In 939 a family of the Taira clan raised arms in the eastern provinces against the imperial authority. Taira-no-Takamochi, a great-grandson of the Emperor Kwammu, had been appointed vice-governor of the province of Kazusa. There his family gradually grew in numbers and influence, some of them becoming provincial governors. Among Takamochi's grandsons was a daring but fierce soldier, Masakado. Though of imperial descent, he obeyed the custom of the time, namely, that every _samurai_ must obtain a livelihood by entering the service of the Fujiwara. Masakado became a vassal of Fujiwara-no-Tadahira, through whose influence he hoped to obtain the office of _kebüshi_. But his aspiration was not satisfied, and being incensed by failure, he returned to the province of Shimōsa, gathered a number of disaffected warriors to his standard, and made organized attacks upon the governors of the neighboring provinces. He established his headquarters at Ishii, in the district of Sashima, nominated certain of his followers to be officers of his court, after the model of the governmental system of Kyōto, and on the strength of being descended from a sovereign, proclaimed himself emperor. In the whole course of Japanese history this is the only instance of a rebellion directed against the throne. Simultaneously with this disturbance in the eastern provinces, Fujiwara-no-Sumitomo, who held the third post in the government of Iyo province in the island of Shikoku, also rebelled. These two rebellions shook the whole empire. Yet the imperial court remained for a long time ignorant of the dangers that were impending. When finally the news reached Kyōto, it caused much consternation. A general was quickly dispatched against the rebels in the east, but before his arrival Masakado's cousin, Taira-no-Sadamori, and Fujiwara-no-Hidesato, the ōryōshi of Shimotsuke, defeated and killed Masakado. In the west, Sumitomo was able for a brief period to retain the ascendency, but he too was ultimately defeated and taken prisoner by Ono-no-Yoshifuru and Minamoto-no-Tsunemoto, who had been sent against him. Tsunemoto was a grandson of the Emperor Seiwa and founder of the renowned clan of Minamoto. The precedent thus established, namely, that of one military clan applying itself to quell the rebellion of another, was followed in after years, with the inevitable result that the military clans became the chief factors in the state.