The Soga clan (蘇我氏 Soga uji) was a prominent family that hailed from Yamato (in modern-day Nara Prefecture). The Soga exercised political power, rivalling that of the Japanese emperors in the 6th​ and 7th​ centuries CE. References in the Nihon Shoki (720) and Kogo Shūi (807) link the family to financial administration, foreign relations and the propagation of Buddhism. The Soga were closely related to the Aya family of Korean descent (帰化人 kikajin).

The family name Soga seems to have derived from a place in the Yamato basin. The Shinsen Shōjiroku (新撰姓氏録), a genealogical compendium dating to the 9th​ century, traces the origins of the Soga to Takenouchi no Sukune (武内宿禰). Some historians believe that the 5th​-century official Soga no Manchi, the first member of the family mentioned in historical sources, is identical to an official of the Korean state of Paekche, whom the Korean chronicle Samguk Sagi refers to as "Mongna Manchi" and the Nihon Shoki as "Moku Manch'i".

Soga no Iname (蘇我稲目, 506-570), the first of four generations of Soga who held the post of ōomi (大臣, chief minister) at the Yamato court, showed much interest in Korean affairs and was one of the first converts to Buddhism, recently introduced from Paekche. In his home, he established a small temple named Mukuharadera (向原寺) to house a Buddhist statue brought from Paekche. Two of his daughters, Soga no Kitashihime and Soga no Oanegimi were married to Emperor Kinmei (欽明天皇 Kinmei-tennō, 509–571), and three of his grandchildren reigned in succession as Emperor Yōmei (r. 585-587), Emperor Sushun (r. 587-592), and Empress Suiko (r. 593-628).

Soga no Umako (蘇我馬子, c. 551-626), Iname's son, sought to establish the Soga family's dominance over the court through kinship ties with the imperial house and patronage of Buddhism. Umako was a stout Buddhist who built the Soga family temple, Asukadera (飛鳥寺), and a man of scholarly interests who helped Prince Shōtoku compile two records, Tennōki and Kokki. The two men introduced several political reforms and worked on promoting Buddhism in Japan. In 587, Umako defeated two of his arch-rivals in battle, the anti-Buddhist and reactionary Mononobe and Nakatomi clans. Despite his Buddhist beliefs, he arranged the assassination of his nephew Prince Anahobe. He installed another nephew, Emperor Sushun (崇峻天皇 Sushun-tennō), who also happened to be his son-in-law, on the throne. When Sushun resisted his autocratic style of government, he had him murdered, too, replacing him with his niece as reigning Empress Suiko (推古天皇 Suiko-tennō, 554-628). He served Suiko as ōomi and collaborated with the empress and her heir-apparent, Prince Shōtoku, to strengthen the central government. Umako showed great hostility to the Korean state of Silla and, in 600, sent a military expedition under his brother Sakaibe no Marise (境部摩理勢) to southeastern Korea.

Umako's son, Soga no Emishi (蘇我蝦夷, 587-645) and grandson, Soga no Iruka (蘇我入鹿, d. 645), continued to exert domination over the throne, abusing their authority increasingly. After Umako's death, Emishi took over his father's position as ōomi. Emishi and Iruka were shrewd and cunning political players and did everything to preserve the Soga family's control of the imperial throne. When Empress Suiko passed away in 628, a succession dispute between Prince Tamura, supported by Emishi and Iruka, and Prince Yamashiro no Ōe, son of Prince Shōtoku, broke out. Prince Tamura prevailed and ascended to the throne as Emperor Jomei (舒明天皇 Jomei-tennō, 593-641). In 641, the Soga were met with great distrust and opposition when they unlawfully requisitioned labourers to build themselves grandiose mausoleums.

After Jomei's death, the Soga intervened again, installing Jomei's widow, Empress Kōgyoku (later Saimei), on the throne. In 643, Iruka attacked the residence of Yamashiro no Ōe, who still threatened his clan and forced him to commit suicide. This action and their blatant abuse of power and governmental funds sealed their fate. Emishi and Iruka seemed to have foreseen trouble and had two fortress-like residences constructed atop a hill west of Asukadera, overlooking the imperial palace. In 645, Prince Naka no Ōe (later Emperor Tenji) conspired with Nakatomi no Kamatari (later Fujiwara no Kamatari), whose family had been eclipsed by the Soga in 580 by planning a coup d'état. During a reception for Korean envoys, Iruka was killed in the audience hall of the palace by Prince Naka no Ōe in what came to be known as the Isshi Incident (乙巳の変 Isshi no Hen). The next day, Emishi - deserted by his militia and remaining supporters - committed suicide. A fire in his residence destroyed the manuscript of the Tennōki; however, a fragment of the Kokki was rescued from the flames. Following Emishi's suicide, Empress Kōgyoku was deposed; the end of the Soga tyranny paved the path for the Taika Reforms, initiated by Naka no Ōe.


Gukei Sumiyoshi: Soga no Iruka's Assassination (Tōnomine Engi Scroll from the Edo period)

Historians suggested that the negative aspects of the Soga rule were deliberately exaggerated by the compilers of the Nihon Shoki and that not much is known about the clan's activities. According to the Taishoku Kanden (大織冠伝), a biography of the Fujiwara clan compiled by Fujiwara no Nakamaro (藤原仲麻呂, 706-764), Iruka and Fujiwara no Kamatari had once studied together under the Chinese priest Min who is said to have praised Iruka's comportment and zeal. Also, several members of the Soga clan had been highly critical of Emishi's and Iruka's excesses. After the coup of 645, the Soga still exerted political influence: Soga no Akae (蘇我赤兄, b. 623), a grandson of Umako, served as ōomi during the Taika Reforms.


Genealogy of the Soga Clan

Source: Kodansha Encyclopedia of Japan


  • Carter, William: Soga family, Kodansha Encyclopedia of Japan, 1983
  • Nussbaum, Louis-Frédéric: Japan Encyclopedia; Cambridge; Harvard University Press, 2005
  • Papinot, Edmond: Historical and Geographical Dictionary of Japan. Reprint from 1910; Tuttle, 1972
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