On December 18, 1416, after Imperial Prince Yoshihito died, Prince Haruhito, who succeeded Imperial Prince Yoshihito, also suddenly died in the following year, on March 8, 1417, and finally Sadafusa became the successor.
応永23年（1416年）11月20日栄仁親王没、翌24年（1417年）2月11日に栄仁親王の後を継いだ治仁王も急死し、貞成が後継となる。