Taira Masakado (平将門)

Taira no Masakado, a member of the Kanmu Taira clan, was the son of Taira no Yoshimasa, a provincial lord in the Kantō region. In 939, Masakado organised a rebellion and attacked the government post of Hitachi (modern-day Ibaraki Prefecture), capturing the governor of the province. In the same year, his rebel army conquered the provinces of Shimotsuke and Kozuke (in present-day Tochigi and Gunma prefectures) and claimed the title of "new emperor". After killing his uncle Taira no Kunika, he was defeated and killed by Fujiwara no Hidesato's forces at the Battle of Kojima (940).


Taira Masakado (平将門, 903-940) was of noble lineage, descending in the fifth generation from Emperor Kanmu (桓武天皇, 737-806), the 50th emperor of Japan. As a young man, Masakado served at the imperial court in Heian -kyō (later known as Kyōto ) and then moved to his home province, the Toyoda and Sashima districts in northern Shimōsa Province (present-day Ibaraki Prefecture). The Shōmonki (将門記), a gunki monogatari (軍記物語) or war tale by an anonymous author who is assumed to have been close to Masakado describes his life.

The insurgency of Taira Masakado in 939-940, known as Tengyō no ran (天慶の乱), ranks among the most dramatic episodes in Japan's early samurai history. The rebellion coincided with earthquakes, rainbows and lunar eclipses in the capital, uprisings in the north, and pirate unrest in the west, and threw the court and the capital in panic. It culminated in Masakado's claiming the title of "new emperor". Many historians view the incident as a harbinger of subsequent events that would enfold from late the Heian Period to the Sengoku Period when the power of provincial warlords reached its zenith.

Taira Masakado (平将門)

Taira Masakado in an Edo-era depiction

The tragedy began in 935 when Masakado was ambushed by another prominent local warrior, Minamoto Tasuku, at a place called Nomoto, near the border region of the provinces of Hitachi, Shimotsuke, Musashi and Shimōsa. Tasuku was the eldest son of Minamoto Mamoru, a mighty warrior and government official in Hitachi. The reason for his grudge against Masakado is unclear, but his attack set a complicated and fateful chain of events in motion. Within a few months, Masakado was at war with several of his relatives. Although taken by surprise, Masakado defeated Tasuku and retaliated, burning and ransacking the residences of Tasuku's supporters in southeastern Hitachi Province, massacring countless civilians. Among the most eminent victims of the Battle of Nomoto were Tasuku, his brothers, and his brother-in-law, Taira Kunika (d. 935), who was Masakado's uncle.

Taira Masakado (平将門)

Masakado (left) as depicted by Angus McBride in Anthony Bryant's "Early Samurai AD 200-1500".
Based on scrolls and reconstruction by Sasama, Nihon Kassen bugujiten.

Over the next four years, Masakado took great care to stay within the limits of imperial law. In 936, he was summoned to court to answer charges filed by Minamoto Mamoru. He managed to convince the Council of State that there were extenuating circumstances for his actions and escaped conviction. He was pardoned two months later when the court declared a general amnesty to celebrate the emperor's coming of age. Masakado returned to Shimōsa but soon again waged war, this time against his father-in-law, Yoshikane. A series of raids and counter-attacks culminated in an attack on Masakado's home in Iwai, Shimōsa Province. Yoshikane's troops surrounded the residence just before dawn, trapping Masakado. Surprisingly, Masakado repelled Yoshikane, killing more than half of his men. Yoshikane himself managed to escape but died a year and a half later.

Meanwhile, Masakado obtained a warrant issued by the Council of State authorising him to arrest Yoshikane, Mamoru, Sadamori and others. Early in 938, however, Masakado received a second summons from the Council of State to question him on another dispute with his cousin Sadamori. Masakado ignored this order and acted on the premise that the mandate from 937 against Sadamori was still in effect. He led his forces to the provincial government of Hitachi province to arrest his cousin Sadamori, who managed to escape before Masakado's troops arrived. Sadamori took refuge in the mountains for several months.

During the eleventh month of 939, Masakado again entered Hitachi province at the head of a large force, allegedly to plead with the provincial government on behalf of one of his supporters. Whatever his intentions, he eventually attacked and occupied the seat of the provincial government and, by that action, crossed the proverbial line. He was no longer just a rural warrior in rivalry with local rivals but an outlaw rebelling against the court. Seeing no means of retreat, Masakado seized, in a rapid succession of raids, the government headquarters of the provinces of Shimotsuke, Kozuke, Musashi, Kazusa, Awa, Sagami, Izu and Shimōsa. Curiously, his next step was to send a letter to his patron, regent Fujiwara Tadahira (880-949), in which he insisted that he had been unjustly slandered and defamed by his enemies and that he had remained in his soul faithful to the imperial law.

The traditional view of things, as reported in the Shōmonki, depicted his conquest of the eastern provinces as the first step in a campaign to make him the ruler of the entire realm. The Shōmonki recounts that Prince Okiyo-ō (興世王), the acting governor of Musashi and one of Masakado's followers, approached him with the bold proposal that now that he had already made himself an outlaw by "striking down one province", he might as well annex the rest of the east and see where it leads. One day, an entertainer and self-declared oracle of the Great Bodhisattva Hachiman predicted that Masakado had been conferred imperial rank; reassured by this prophecy, Masakado went on to appoint his court and bureaucracy and to lay plans for the construction of a new imperial palace in Shimōsa. It is unlikely, however, that any of these events ever occurred in reality. None of the imperial proclamations and documents relating to his case mentioned Masakado assuming the title of "new emperor" (新王 shin-ō), the construction of a new imperial palace or the appointment of new government officials, which would appear quite unusual in the light of the hysteria and paranoia that took hold of the court in 940. More likely, Masakado's intention after the debacle in Hitachi Province was to establish a position of strength to take advantage of the court's preoccupation with natural disasters, bandit activities in the north and the capital region, and piracy in the west to negotiate a pardon.

Within a month, however, the court issued edicts calling for the apprehension of Masakado. It commanded several notable warriors for this task, including his cousin Sadamori and Fujiwara Hidesato, his former ally. On the fourteenth day of the second month of 940, the court's army caught up with Masakado in northwestern Shimōsa Province. Outnumbered by more than ten to one, Masakado's troops were quickly routed, and an arrow killed him. On the tenth day of the fifth month, Hidesato and Sadamori brought Masakado's head to the capital, where it was put on display.

Taira Masakado (平将門)

Masakado's head on display in Kyōto


According to legend, Masakado's severed head would gnash its teeth for weeks and then fly off to the east, landing in Shibasaki, a small fishing village close to what would later become Edo (and eventually Tōkyō). Kind souls buried it in a "head mound" (首塚 kubizuka), where it has been venerated ever since. Over the centuries, Masakado had turned into a sort of deity, worshipped for taking a stand against a - at least in his view - oppressive imperial government and feared for his vengeful spirit. He was later enshrined in Kanda Myōjin and Tsukudo Jinja.

Read more on Masakado Kubizuka.


Tsukioka Yoshitoshi: Sagami Jirō and Taira no Masakado attacking an opponent on horseback (woodblock print, 19th century)


  • Bryant, Anthony J., Early Samurai AD 200-1500, Osprey Elite 1991
  • Friday, Karl, The First Samurai: The Life & Legend of the Warrior Rebel Taira Masakado, Wiley 2008
  • Nussbaum, Louis Frédéric, Japan Encyclopedia, Harvard 2005
  • Rizō, Takeuchi, The Rise of the Warriors, in The Cambridge History of Japan, Vol.2, Heian Japan, Cambridge University Press 1999