Given the above situation, Emperor Saga's nephew, Prince Takaoka, became the crown prince after the Emperor's enthronement, and a year later (810) there was "the Revolt of Kusuko," when Emperor Heizei attempted to regain the throne.
このような事情から即位後に甥にあたる高岳親王を皇太子としたが、翌年810年に平城天皇が復位を試みた「薬子の変」が発生する。