Final answer:
The struggle between the Taira and the Minamoto families from 1180 to 1185 was decided in the Genpei War, leading to the triumph of the Minamoto family and the start of the Kamakura period of Japan's history.
Step-by-step explanation:
The struggle between the two major provincial families, the Taira and the Minamoto, between 1180 and 1185 was decided in the Genpei War. This was an uprising where the Minamoto family triumphed, winning the naval Battle of Dannoura in 1185. The outcome of this war signaled the start of the Kamakura period of Japan's history, during which the warrior families, first the Minamoto and then the Hojo, were headquartered in Kamakura. Yoritomo, the heir of the Minamoto clan, successfully eliminated all rivals with the help of the samurai, leading to the military shogunate competent in state power while the emperor served as a mere figurehead.
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