According to the 'Kudarahonki' (Original records of Paekche) quoted by "Nihonshoki" (Chronicles of Japan), a legend has it that Emperor Keitai and Prince died together around 531, and another theory has it that after the death of Emperor Keitai, two Imperial Courts existed at the same time, one was reigned by Emperor Ankan and Emperor Senka, the other was reigned by Emperor Kinmei, and they had a domestic conflict ('Shingai Coup' theory).
なお、『日本書紀』に引く「百済本記」（「百濟本記爲文其文云大歳辛亥三月軍進至于安羅營乞乇城是月高麗弑其王安又聞日本天皇及太子皇子倶崩薨由此而言辛亥之歳當廿五年矣」）によれば、531年頃に天皇と太子・皇子が共に薨去したという所伝があるといい、継体天皇の死後、安閑天皇・宣化天皇の朝廷と欽明天皇の朝廷が並立していたとか、2朝間に内乱があったと見る説もある（「辛亥の変」説）。