Emperor Antoku

Antoku (1178–1185), son of Emperor Takakura and grandson of Taira no Kiyomori, was named crown prince at about a month old. He was enthroned in 1180, with Kiyomori ruling in his name.

When the Minamoto seized Kyoto in 1183, the Taira fled west with the boy, and the court enthroned Go-Toba. At the Battle of Dan-no-ura in April 1185 the Taira were destroyed; his grandmother clasped the six-year-old emperor and drowned with him in the Shimonoseki Straits, and the sacred sword was lost.