The name "Genpei" comes from alternate readings of the kanji "Minamoto" (源 Gen) and "Taira" (平 Hei).

Along with the Minamoto, Taira was one of the honorary surnames given by the emperors of the Heian period (794–1185) to their children and grandchildren who were not considered eligible for the throne.

One was founded in 889 by Taira no Takamochi (great-grandson of the 50th Emperor Kanmu, who reigned from 781 to 806) proved to be the strongest and most dominant line during the Heian period.

[6] A great-grandson of Takamochi, Taira no Korehira, moved to Ise Province (currently part of Mie Prefecture) and established an important Daimyo dynasty.

Taira no Kiyomori gained power in Kyoto forging alliances with retired emperors Shirakawa and Toba.

In 1192, Minamoto no Yoritomo received the title shogun and created the first bakufu based in Kamakura (Kanagawa Prefecture).

The mon (crest, emblem) of the Taira clan is an Agehanochō (揚羽蝶, Swallowtail butterfly) with raised wings.