Battle of Dan-no-ura
During this time, the Imperial family was involved in a bitter struggle between warring clans. Minamoto no Yoritomo with his cousin Minamoto no Yoshinaka, led a force from the Minamoto clan against the Taira, who controlled the emperor. During the climactic sea Battle of Dan-no-ura in April 1185, Antoku's grandmother Taira no Tokiko took him and plunged with him into the water in the Shimonoseki Straits, drowning the child emperor rather than allowing him to be captured by the opposing forces.