After his father, the Cloistered Emperor Kameyama died when he was three years old, he inherited most of his father's assets due to his father's will, he ordered his grandchild, Emperor Gonijo to let Imperial Prince Tsuneaki succeed to the throne for next Emperor from the Daikakuji Imperial line, instead of Emperor's eldest Prince, Imperial Prince Kuniyoshi, also pronounced Kuninaga.
3歳の時、父である亀山法皇が病死するが遺詔でその財産の多くを与えた上に、自分の孫に当たる後二条天皇に対しては次の大覚寺統の皇位は天皇の嫡男邦良親王ではなく、恒明親王を立てるように命じたのである。