For these reasons, Imperial Prince Atsunari, the younger half brother of Imperial Prince Atsuyasu by a different mother, was made heir apparent to the throne at the age of only four on the occasion of abdication of the Emperor Ichijo, which took place 10 days after the conferment of the rank of Ippon on Imperial Prince Atsuyasu.
このため、敦康親王叙一品の十日後、一条天皇譲位で皇太子に立てられたのはわずか四歳の異母弟敦成親王であった。