The Nakatomi clan, ancestors of the Fujiwara, were also Shinto ritualists allied with the Mononobe in opposition to Buddhism.
The Mononobe were said to have been descended from Nigihayahi no Mikoto, (饒速日命), a legendary figure who is said to have ruled Yamato before the conquest of Emperor Jimmu.
His descendant Mononobe no Toochine (物部十千根), known as the founder of the clan, was given Isonokami Shrine by Yamatohime-no-mikoto, the daughter of Emperor Suinin.
According to the Nihon Shoki, one particularly important conflict occurred after the Emperor Yōmei died after a very short reign.
Mononobe no Moriya, the head of the clan, supported one prince to succeed Yōmei, while Soga no Umako chose another.