Since the Emperor Keitai entered Yamato not immediately after the enthronement but the 20th year later after moving from place to place such as Kitakawachi or Minami-yamashiro, there are two following theories: One that considers due to a power in Yamato which didn't allow the enthronement of Emperor Keitai, the region was in the combat situation (theory by Kojiro NAOKI) and the other that, since Keitai, the emperor of the maternal side, was a successor to the throne in the linage of the Okinaga clan in Omi, which daughters often married those in the great king family, there was no such change of dynasties as usurpation of imperial throne (theory by Kunio HIRANO).
また、即位後もすぐには大和の地にはいらず、北河内や南山城などの地域を転々とし、即位20年目に大和にはいったことから、大和には継体天皇の即位を認めない勢力があって戦闘状態にあったと考える説（直木孝次郎説）や、継体天皇は女系の天皇で、近江の息長氏などは大王家に妃を何度となく入れているが、継体天皇はその大王家の母方といえる息長氏系統の王位継承資格者で、皇位簒奪のような王朝交替はなかったと考える説（平野邦雄説）がある。