According to "Nihonshoki", Emperor Chuai intended to keep swans in the pond that surrounded the mausoleum in memory of his father, YAMATO Takeru no Mikoto, and ordered countries to present swans.
『日本書紀』によると、仲哀天皇は白鳥となって天に昇った父・日本武尊をしのんで、陵を囲む池に白鳥を飼おうと考えて、諸国に白鳥を献上するよう命じた。