Fujiwara Mototsune had continued the trend begun by Yoshifusa of monopolizing the position of regent to the Japanese emperor.
He was third son of Fujiwara no Nagayoshi, brother of Yoshifusa, and Fujiwara no Otoharu, daughter of Fujiwara no Tsugutada.
He was adopted by Yoshifusa who had no sons, and Mototsune followed in Yoshifusa's footsteps.
After the emperor had reached his maturity, however, Mototsune invents the position of kampaku regent for himself.
This innovation allowed the Fujiwara clan to tighten its grip on power right throughout an emperor's reign.
Mototsune thus becomes, in 884, Japan’s first official civil dictator.
Emperor Yozei of Japan is deposed, and succeeded by his paternal great-uncle Emperor Kōkō.
