Prince Nagaya was a grandson of Emperor Tenmu and the son of Prince Takechi. His wife Kibi was a daughter of Empress Genmei. By the late 720s he held senior ministerial authority at the Nara court, where Emperor Shōmu ruled and the sons of Fujiwara no Fuhito were gaining influence.
Nagaya's residence also hosted literary gatherings. Satō Makoto reads the Kaifūsō, compiled in 751, as evidence for a cultural circle receiving Silla guests and exchanging Chinese poetry. Its lists of poems and participants connect Nagaya with learned officials, people from immigrant-descended families and writers who had studied on the continent. The collection is a later literary witness to those occasions, not a transcript made by an observer at each gathering.
Among the participants Satō lists Fujiwara no Fusasaki and Fujiwara no Umakai. Their presence is a specific relationship within cultural activity, not proof of permanent political agreement. It makes an account of wholly separated “imperial” and “Fujiwara” worlds harder to sustain. Satō describes the distribution of characters to establish rhymes and interprets the poems as evidence of music, dance, food and drink. The literary forms preserve how learning could organize a reception; they do not license reconstruction of a particular evening's private conversation.
Buddhist patronage produced another kind of written work. In 712 Nagaya commissioned the Great Perfection of Wisdom Sutra for Monmu's memorial. The Imperial Household Agency's description identifies a surviving volume and the relationship: the dead ruler was Kibi's brother, making Nagaya his brother-in-law. It also distinguishes an original scroll format from later folding-book form. A commissioning act, a family memorial and a transmitted object belong to the same project without being identical things.
In 728 another six-hundred-volume commission sought merit for Nagaya's deceased parents, for the reigning Shōmu and for earlier sovereigns. The museum description of a fragment from volume 465 identifies the dedication's “Buddhist disciple, Prince Naga” with Nagaya. This supplies a declared religious purpose that can be stated without guessing his complete private motives. A scholar may ask what favor or security he sought, but the surviving dedication should not become proof that his practice was aimed at overthrowing the state.
Another continental connection survives in the biography of Ganjin compiled in 779. Satō cites its tradition that Nagaya sent a thousand robes for monks in China, with verse on their collars joining separate lands through a shared sky and a hoped-for Buddhist connection. The account says Ganjin knew that message while still in China. It gives the prince's religious patronage a later continental witness, without preserving the delivery of every robe or a personal meeting between the two men. This tradition, scripture dedications and the later charge of illicit practice belong to different kinds of evidence.
In 729, informants accused Nagaya of a plot involving sorcery. The Shoku Nihongi records troops surrounding his residence and court dignitaries questioning him there. The court ordered Nagaya to take his own life; Kibi and their four sons also died by suicide. The chronicle subsequently declared Kibi innocent and pardoned other relatives. Shōmu's consort Kōmyō, Fuhito's daughter, became empress later that year. That advancement helped the Fujiwara family, but does not by itself establish who organized the accusations. The Shoku Nihongi, the court history completed in 797, later describes one of Nagaya's accusers as having made a false accusation.
The political record is only one part of the surviving evidence. Excavations in 1988 recovered about 35,000 wooden documents from Nagaya's household, dating mainly to 710–717. Food-issue tickets and administrative correspondence identify an estate with managers, dependants, and regular supplies. These earlier records make the household behind the destroyed residence unusually visible; they are not a dossier of the 729 prosecution.
Two informants alleged in 729 that Nagaya secretly studied illicit practices and intended to overturn the state. Kimoto Yoshinobu reproduces the Shoku Nihongi account: on the night of the accusation, the court secured the three strategic barriers and sent troops to surround the residence. Fujiwara no Umakai and guard officers led the operation. The distinction between allegation and action is essential. The record establishes what was reported and what the court ordered; its report of the charge is not independent proof that the alleged conspiracy occurred.
A delegation then questioned Nagaya. Kimoto's quoted list includes Princes Toneri and Niitabe, together with senior officials including Fujiwara no Muchimaro. Their participation shows why the crisis cannot be explained by imperial genealogy alone. Princes from Nagaya's own extended imperial family took part in the court's inquiry. The leading minister was already inside a residence held under armed control, while questioning proceeded through a delegation carrying authority from the court.
The court ordered Nagaya to take his own life. Kibi and their four sons—Kashiwade, Kuwata, Katsuragi and Kagitori—also died. The household's people were seized and detained in guard offices. Other branches had a different fate: Fuhito's daughter and her children survived, and many relatives and dependants were subsequently released. The distinction is necessary both to count the human loss and to avoid making the whole household disappear under one indiscriminate sentence.
Kōmyō became empress later that year.
Historical disagreement · Who planned Nagaya’s destruction?
Several accounts connect Nagaya's destruction with anticipated opposition to her appointment and the succession difficulties following an infant heir's death. Those interpretations organize the political circumstances; they do not establish one uncontested planner. Kimoto records a debate between Nakagawa Osamu's account of the Fujiwara brothers' cooperation and Takinami Sadako's separation of Muchimaro from Fusasaki, supporting the latter while acknowledging that the Muchimaro-instigator explanation is not settled consensus.
Fusasaki's absence from the named operation is a piece of the argument, not conclusive proof of his innocence.
The household records answer questions about administration and identity that the crisis narrative leaves aside. They cannot, by identifying Nagaya's residence, identify the author of the accusation. Nor does the rapid enclosure and death establish every private intention assigned to Shōmu, Kōmyō or the four brothers. The firm sequence is accusation, military containment, inquiry and ordered death, followed by differentiated treatment of survivors. It removed a leading minister and devastated a particular imperial household.
The court ordered Nagaya and Kibi buried on Mount Ikoma. Yamamoto Takashi points out a distinction within the Shoku Nihongi account: Kibi was declared without guilt and was to receive ordinary burial observances; Nagaya's burial was not to be made degrading, despite the court's treatment of him as a guilty person. The command is evidence for official treatment after death. It does not retroactively prove the accusation or cancel the family's loss.
The Nihon Ryōiki offered a different causal sequence. Its story begins with Nagaya striking a novice with an ivory tablet and reads the subsequent charge as retribution. It describes the family's bodies being burned and dispersed, with the prince's bones carried to Tosa and later moved to an island off Kii after people attributed deaths to his harmful presence. Those details belong to a religious tale whose explanation conflicts with the chronicle's burial account. The tale is important evidence of meaning attached to his fall, not proof of supernatural causation.
A tomb tradition near Arida in Kii drew on that account. Its associated mound was found in 1908, but the mound's construction belonged to an earlier burial period. The existence of a revered place therefore does not establish it as Nagaya's 729 grave. The difference between recorded burial, a tale of wandering bones and a later local association closes his life with several kinds of memory still distinguishable. His ministerial acts, literary relationships and household's destruction can be read without requiring those different witnesses to agree on one explanation.
Nagaya became senior counsellor in 718. After Fuhito died in 720, he rose to right minister in 721. During Genmei’s final illness that year, she entrusted affairs to Nagaya and Fujiwara no Fusasaki. The change placed him at the head of the ministers, but not alone at the summit of imperial administration. Yokota notes that Prince Toneri had received responsibility for overseeing the Council of State and Prince Niitabe for guards. Senior authority was distributed among people with different titles and responsibilities. The phrase “Nagaya's government” should therefore locate leadership within that arrangement rather than erase the other princes.
In 722 the government set a target of reclaiming a million chō of good land. Yoshida Takashi describes provincial and district officers supplying food to recruited laborers, with service limited to ten days and tools lent from public stores. Officers who neglected the work faced removal.
Historical disagreement · What land did the million-chō plan target?
The target's reach is disputed: scholars differ over a national project or one centered on the northeastern frontier, and over wet-rice fields or upland cultivation.
The announced scale should not be mistaken for an achieved increase of a million chō. Its relationship to the following year's law also remains debated.
