When Obitono-oji succeeded to the throne after Fuhito's death, there arose a conflict between the four sons of Fuhito (four Fujiwara brothers) and their opponents led by Nagayao, which deepened as time progressed.
不比等の死後、首皇子が皇位に就くと、不比等の4人の男子（藤原四兄弟）と長屋王ら反対派の対立が深まっていった。