The Taira clan (平氏)
The family name of the Taira clan was derived from "TAIRA no Ason," which was one of the official titles given to a member of the Imperial Family if they became vassals. A swallowtail butterfly was the representative Kamon (family crest) of the Taira clan.
Summary
While the family names of Minamoto and Taira were both conferred on princes and princesses, many of those who received the title of Taira were said to have been the emperor's grandchildren or more distant relatives; therefore, the Taira clan was considered to hold a lower rank than the Minamoto clan. While the origin of the name 'Taira' is unknown, the most influential theory proposed by Akira OTA and developed by Kunihiko FUJIKI, Arikiyo SAEKI and others, states that "Taira" derives from a Japanese reading of the kanji character "平" in "平安京," the ancient capital in present-day Kyoto which was built by the Emperor Kanmu, an ancestor of the first Taira clan, Kanmu-Heishi. Masahiko YASUDA also supports this theory but makes the point that the name could also have come from the Chinese classics, as the names of Minamoto and Ariwara clans did.
There were four Taira clan lineages; the Kanmu-Heishi descended from Emperor Kanmu, Ninmyo-Heishi (Taira clan) descended from Emperor Ninmyo, Montoku-Heishi (Taira clan) descended from Emperor Montoku, and Koko-Heishi (Taira clan) descended from Emperor Koko. Of these, the only lineage to produce famous samurai families was the Kanmu-Heishi lineage, which included the following branches: the Ise-Heishi, from which the Heike (the family of TAIRA no Kiyomori that established the Taira clan government) was descended; and the Bando-Heishi, from which the Hojo clan (which became regents of the Kamakura bakufu, a Japanese feudal government headed by a shogun) was descended. This is the reason why the Taira clan generally refers to the Kanmu-Heishi lineage.
It is generally believed that the Minamoto clan ruled the Togoku (the eastern part of Japan, particularly the Kanto region), while the Taira clan held power in the Saigoku (the western part of Japan, particularly Kyushu but ranging as far east as Kinki), but members of the Taira clan could also be found in the Togoku as well. In fact, it would be more appropriate to say that the influence of the samurai of Taira lineage first covered the Togoku where many imperial princes were appointed to the governors of provinces, and later the Taira clan expanded their sphere of influence to the center (the Imperial court) and to the Saigoku. Famous members of the Taira clan included the following: TAIRA no Masakado of Shimousa Province and Hitachi Province, who tried but failed to establish an independent government in Togoku; TAIRA no Kiyomori, who led the aristocratic government; and the Bando-Heishi, supporters of MINAMOTO no Yoritomo, who had toppled Kiyomori; ironically, both Kiyomori and the Bando-Heishi could trace their ancestry back to the lineage of the Taira clan that was native to the Togoku.
This shared ancestry is the reason why the conflict is referred to as 'the conflict between the Minamoto clan and Heike (family of TAIRA no Kiyomori),' not as the 'conflict between the Minamoto clan and the Taira clan.'
The Fujiwara clan successfully introduced the Ritsuryo system (a system of centralized government based on the ritsuryo code) between the years 600 and 700; specifically, one of the Fujiwara clan lines, the Northern House of the Fujiwara clan, established its foundations in Togoku (the Utsunomiya clan, the Oda clan, the Nasu clan, the Koyama clan, the Yuki clan, the Sano clan, the Hiki clan, etc.). Prior to the compilation of Taiho Code, the Yamato kingdom (ancient kingdom of Japan) summoned SHIMOTSUKENU no Komaro who was a member of the local ruling family SHIMOTSUKENU in Shimotsuke Province (present-day Tochigi Prefecture) in Togoku, to be engaged in compilation of the codes with FUJIWARA no Fuhito.
Thereafter, the Kanmu-Heishi, which was descended from the fiftieth Emperor Kanmu, took over Togoku (Hitachi Province, Kazusa Province and Kozuke Province) by appointing imperial princes to the governors of the provinces. It is considered that this expansion of their own territory supported the rise of the Taira clan in the late Heian period. The famous Bando-Heishi clans included the Kamakura, Miura, Chiba, Kazusa, Chichibu, Daijo, Nakamura, Nagao, and Kajiwara.
Meanwhile, the Seiwa-Genji branch of the Minamoto clan (who were descended from Emperor Seiwa, the fifty-sixth emperor) and particularly the Kawachi-Genji branch of the Minamoto clan (which was known as the head of the samurai families based in Kawachi Province, which was located in the Kinai region) prevented the privileged classes (clans such as the Taira and Fujiwara) from assuming power and steadily extended the power base of the Minamoto clan throughout the Togoku. The famous Minamoto clans in the Bando (old Kanto) region descended from the Kawachi-Genji included the Nitta, Ashikaga, Satake, Takeda, Ogasawara, and Satomi.
Families of the Bando-Heishi clan either became retainers for or rebelled against and suppressed by the Genji and Fujiwara clans, and thus hardly left their marks on the history of Togoku, while TAIRA no Kiyomori who came from the Ise-Heishi ruled Saigoku and controlled the central government. After MINAMOTO no Yoritomo, who was descended from the Bando-Genji line of the Kawachi-Genji, rebelled against and defeated the Taira clan, he founded the Kamakura bakufu in Togoku, but Yoshisada NITTA and Takauji ASHIKAGA, under orders from Emperor Godaigo, toppled the Kamakura bakufu, which had been taken over by the Bando-Heishi, and contributed to the establishment of a new central government; moreover, the Kamakura, Muromachi and Edo bakufu were feudal governments administered by the Bando-Genji. These facts are probably the basis of general belief that the Minamoto clan ruled the Togoku while the Taira clan had influence over the Saigoku.
Only a few clans, such as the Ise-Heishi, retained the Taira surname (the same kanji character is used for both "Hei" and "Taira.")
Although it was a branch of the Ise-Heishi clan, the term 'Heike' (Taira family) specifically refers to TAIRA no Kiyomori, who established the so-called Heishi government, and members of his family. In contrast, many families of the Minamoto clan used the Minamoto surname and were collectively referred to as Genji (the Minamoto clan); and the term Genke, referring to a single Minamoto family, is rarely used.
The Kanmu-Heishi
The Kanmu-Heishi were established by some lower ranked grandsons of Emperor Kanmu who had been given the honorary surname of 'TAIRA no Ason' upon being demoted from the Imperial family in and after 825. They can be broadly classified into four lineages according to the founders who were sons of the Emperor Kanmu. The most prosperous lineage was that of Imperial Prince Kazurawara, and the other three lineages were those of Imperial Prince Manda, Imperial Prince Nakano and Imperial Prince Kaya.
The lineage of Imperial Prince Kazurawara
This is one of the four Kanmu-Heishi lineages followed by the two well-known lineages: the Prince Takamune lineage of court nobles which originates from Prince Takamune, the first son of the Imperial Prince Kazurawara who was named TAIRA no Takamune on demotion from the Imperial family; and the Prince Takamochi lineage of samurai families which originates from Prince Takamochi, a son of the Prince Takami (the third son of the Imperial Prince Kazurawara) who was named TAIRA no Takamochi on demotion from the Imperial family.
The lineage of Prince Takamune
They were the descendants of Prince Takamune, the first son of Imperial Prince Kazurawara who was named TAIRA no Takamune when a surname was conferred in 825. Members of this lineage became court nobles and remained in Kyoto; in the late Heian period, the following prominent figures came from this lineage: TAIRA no Tokiko (Nii no Ama), the lawful wife of TAIRA no Kiyomori (from the lineage of the Prince Takamochi); TAIRA no Tokitada, Tokiko's brother, who was promoted to Dainagon (Major Counselor) of Shonii (Senior Second Rank) owing to Kiyomori's influence; and Kenshunmonin TAIRA no Shigeko, their half-sister. After the Battle of Dan no ura, Tokitada was exiled to the Noto Province and died there, but the descendants of his brother TAIRA no Chikamune (the Karahashi family) and those of his uncle TAIRA no Nobunori (the Nishinotoin family, the Agoin family and the Karasumaru family) survived as court nobles through the Kamakura period. The Nishinotoin family in particular survived into the Edo period, and this head family and four branch families became Tosho-ke (the hereditary lineage of court nobles occupying relatively high ranks).
In addition, families identifying themselves as descendants of Tokikuni, a son of Tokitada, became wealthy farmers in the Noto peninsula (the Kamitokikuni family and the Shimotokikuni family), and exist to this day.
The lineage of Prince Takamochi
This lineage originated with Prince Takamochi, a son of Prince Takami (the third son of Imperial Prince Kazurawara) who, having been given an honorary surname, was named TAIRA no Takamochi. However, since the name of the Prince Takami is not found in historical sources from the relevant period, there is some doubt about this lineage.
(Both last kanji characters in Takamochi (望) and Takami (見) can be read as 'mi' in Japanese reading.)
Based on a record stating that the surname of 'Taira no Ason' was conferred on five imperial princes (of unknown names) in 889, it is assumed that Prince Takamochi was one of them.
The Bando-Heishi
Takamochi was appointed as kokushi (provincial governor) of Kazusa Province in 898. While many other kokushi stayed in Kyoto (so-called Yonin Kokushi), Takamochi left the capital and went into the province with his sons TAIRA no Kunika, TAIRA no Yoshikane and TAIRA no Yoshimasa. Takamochi did not return to Kyoto after he served out his term, and his sons Kunika filled the post of Hitachi no daijo (Senior Secretary of Hitachi Province) and Yoshimasa of Chinju-fu shogun (Commander-in-Chief of the Defense of the North). They expanded their power from Kazusa Province into Hitachi Province and Shimousa Province, forming armed groups in the Bando (old Kanto) region, which became the foundation of the Taira clan as samurai. TAIRA no Yoshifumi, a son of Takamochi's concubine, also left Kyoto for Bando, and his descendants formed samurai clans such as the Miura, Doi, Chichibu and Chiba in various locations across Bando. The Bando-Heishi of the Yoshifumi linage are specifically referred to as the Bando Hachi Heishi (the Eight Taira Clans of the East).
The Ise-Heishi and Heike
TAIRA no Korehira, a grandson of Kunika, was the founder of a clan called the Ise-Heishi. The Ise-Heishi branch of the Taira clan, and those descended from TAIRA no Masamori in particular, are specifically called the Heike (Taira family). Masanori's son, TAIRA no Tadamori, was the first member of the family to be granted access to the Imperial court, and Tadamori's son (Kiyomori) established the Heike-dominated government and became extremely powerful; the proud and arrogant Heike were not to last for long, however, and they were destroyed in the Battle of Dan no ura.
Heike no Ochiudo (Heike fugitives from the Genpei War) scattered across the country to live their lives in secrecy, and many samurai families that identified themselves as descendants of the Ochiudo included the Tanegashima clan in Satsuma Province, the So clan in Tsushima Province, and the Oda clan in Owari Province. However, these are likely to have been descendants of retainers who served the Heike, rather than actual members of the Heike family (according to another theory, the Oda clan was descended from the Fujiwara clan).
Examples of the hiding villages of the Heike no Ochiudo include Gokanosho in Kumamoto Prefecture and Gokayama in Toyama Prefecture.
These so-called hiding villages for the surviving Heike fighters, their families and retainers are commonly called 'Heike-dani (villages of Heike fugitives).'
The Muromachi period saw the completion of the "Heike Monogatari" (The Tale of the Heike), an epic account of the Genpei War that has been widely read up to this day.
The Ninmyo-Heishi
This clan originated with the descendents of Prince Masamochi, Prince Yukitada, and Prince Koretoki (all of whom were grandsons of Emperor Ninmyo), who were given the honorary surname of Taira no Ason upon being demoted from the Imperial family.
It should be noted that some documents define the Ninmyo-Heishi as 'the clan originating with the descendants of Imperial Prince Motoyasu, a son of Emperor Ninmyo, who were given the surname of 'Taira no Ason' upon being demoted from the Imperial family.'
This definition is implausible because some of Imperial Prince Motoyasu's sons were given the surname of Minamoto no Ason and became Ninmyo-Genji, such as MINAMOTO no Kaneji (源兼似), MINAMOTO no Kanehito (源兼仁), MINAMOTO no Chogan (源朝鑑), MINAMOTO no Yasumochi (源保望), and MINAMOTO no Yoshimichi (源由道). It is therefore correct to define the descendants of Prince Masamochi, Prince Yukitada and Prince Koretoki as the Ninmyo-Heishi.
The Montoku-Heishi
This clan originated with the descendants of Imperial Prince Korehiko (Emperor Montoku's son), who were given the honorary surname of Taira no Ason upon being demoted from the Imperial family.
The Koko-Heishi
This clan originated with descendants of Prince Shikisen and Prince Koga (grandchildren of Emperor Koko), who were given the honorary surname of Taira no Ason upon being demoted from the Imperial family.
It should be noted that some documents define the Koko-Heishi as 'the clan originating with the descendants of Imperial Prince Koretada, a son of Emperor Koko, who were given the surname of 'Taira no Ason' upon being demoted from the Imperial family.'
This definition is implausible because some descendants of Imperial Prince Koretada who were given the surname 'Minamoto no Ason' became the Koko-Genji; an example of this is MINAMOTO no Yasunao, a son of MINAMOTO no Yasuyuki, whose grandfather Prince Eiga was a son of Imperial Prince Koretada. It is therefore correct to define the descendants of Prince Shikisen and Prince Koga as the Koko-Heishi. TAIRA no Nakaki, the grandchild of TAIRA no Takamune, was adopted by Prince Tadamochi, a son of Imperial Prince Koretada, and therefore added into the Prince Takamune lineage of the Kanmu-Heishi, but Nakaki's descendants were Koko-Heishi. Hence, TAIRA no Motonori (the son of Nakaki) was Koko-Heishi.