Battle of Dan - no - ura The was a major sea battle of the Genpei War , occurring at Dan - no - ura , in the Shimonoseki Strait off the southern tip of Honshū . On March 24 , 1185 , the Genji ( Minamoto ) clan fleet , led by Minamoto no Yoshitsune , defeated the Heike ( Taira ) clan fleet , during a half - day engagement . The Taira were outnumbered , but some sources say that they had the advantage over the Minamoto in understanding the tides of that particular area , as well as naval combat tactics in general . The Taira split their fleet into three squadrons , while their enemy arrived en masse , their ships abreast , and archers ready . The beginning of the battle consisted mainly of a long - range archery exchange , before the Taira took the initiative , using the tides to help them try to surround the enemy ships . They engaged the Minamoto , and the archery from a distance eventually gave way to hand - to - hand combat with swords and daggers after the crews of the ships boarded each other . However , the tide changed , and the advantage was given back to the Minamoto . One of the crucial factors that allowed the Minamoto to win the battle was that a Taira general by the name of Taguchi Shigeyoshi defected , and revealed to the Minamoto which ship the six - year - old Emperor Antoku was on . Their archers turned their attention to the helmsmen and rowers of the Emperor ' s ship , as well as the rest of their enemy ' s fleet , sending their ships out of control . Many of the Taira warriors , including Taira no Tomomori , Taira no Tsunemori and Taira no Norimori , as they saw the battle turn against them , threw themselves overboard , committing suicide rather than having to face defeat at the hands of the Minamoto . Among those who perished this way were Antoku and his grandmother , the widow of Taira no Kiyomori , head of the clan . To this day , the Heike Crabs found in the Straits of Shimonoseki are considered by the Japanese to hold the spirits of the Taira warriors . The Taira attempted to toss the imperial regalia off the ship but only managed to get the sword and mirror into the water before the ship holding the regalia was captured . The mirror was recovered by divers ; many presume the sword to have been lost at this time , though it is officially said to have been recovered and enshrined at Atsuta Shrine . This decisive defeat of the Taira forces led to the end of the Taira bid for control of Japan . Minamoto Yoritomo , the elder half - brother of Minamoto Yoshitsune , became the first Shogun , establishing his military government ( ' bakufu ' ) in Kamakura . In this battle the Taira lost Taira Tomomori , Taira Noritsune , Taira Norimori , Taira Tsunemori , Taira Sukemori , Taira Arimori and Taira Yukimori were killed . In popular culture . In 1965 , a dramatized version of the battle dated for March 24 , 1185 appeared as part of the movie " Kwaidan " . In his book and television series " " , Carl Sagan presents a brief , dramatic account of the battle in chapter / episode 2 ; " One Voice in the Cosmic Fugue " . Sagan then uses the Heike crabs as examples of artificial selection . In the anime film " Pom Poko " , by Studio Ghibli , one of the venerable Shape - Shifting Tanuki Masters is an eyewitness to the battle and delights in telling the Tama Tanuki of his exploits , where he was responsible for firing the first critical shot of the battle disguised as one of the mounted archers . In " " ( a Japanese remake of the spaghetti Western movie " A Fistful of Dollars " ) , this battle is referred to as part of the film ' s backstory . The battle is also recounted near the beginning of the Usagi Yojimbo story arc " Grasscutter " . See also . According to Shimonoseki City Information : " In the Middle Age , the last battle between the Genji clan and the Heike clan broke out in Dannoura on 24 March 1185 and Yoshitsune won the battle by using the tides . On the other hand , Emperor Antoku died with three sacred treasures and the Heike clan was ruined . "