December, 805 (Enryaku 24).
Emperor Kanmu engaged two councilors in a debate about the governance of the realm.
These councilors were Fujiwara no Otsugu and Sugano no Mamichi.
Otsugu raised concerns about “military affairs” and “construction projects.”
These included the ongoing campaigns against the Emishi in the northeast.
And the construction of the Heian Palace and Heian-kyo.
Both were major state projects pursued throughout Emperor Kanmu’s reign.
Otsugu argued that these were causing hardship for the people and called for their suspension.
Sugano no Mamichi opposed this view, but Emperor Kanmu ultimately sided with Otsugu.
This marked a significant turning point for the campaigns and city-building efforts that had persisted for over twenty years.
Emperor Kanmu’s reign lasted about 25 years.
During this period, the capital moved from Heijo-kyo to Nagaoka-kyo, and then to Heian-kyo.
In the northeast, large-scale military operations were repeatedly conducted, and after resistance from leaders like Aterui, Sakanoue no Tamuramaro advanced into Isawa.
The military system and local administration were also reformed, and in 804, an envoy was sent to Tang China.
This delegation included Saicho and Kukai.
From the Nara period to the Heian period.
Emperor Kanmu’s life coincided with this major transitional era.
1. 737—Born as Prince Yamabe
737 (Tenpyo 9).
The future Emperor Kanmu was born as the son of Prince Shirakabe.
His name was Yamabe.
His father, Prince Shirakabe, was a grandson of Emperor Tenji and later became Emperor Kōnin.
His mother was Takano no Niigasa.
She was said to be from a family connected to the Baekje immigrants.
Prince Yamabe was not initially at the center of the line of succession.
When Empress Shotoku passed away in 770 (Hoki 1), his father, Prince Shirakabe, ascended the throne as Emperor Kōnin.
In the following year, 771, it was not Prince Yamabe but his half-brother, Prince Osabe, who was named Crown Prince.
Prince Osabe’s mother, Empress Inoe, was the daughter of Emperor Shomu.
He was a prince with imperial lineage from Emperor Tenji on his father’s side and Emperor Shomu on his mother’s side.
However, this position did not last long.
2. 772–773—The Deposition of Crown Prince Osabe and Prince Yamabe
772 (Hoki 3).
Empress Inoe was accused of cursing Emperor Kōnin and was deposed.
Her son, Crown Prince Osabe, was also stripped of his title in May.
In January of the following year, 773.
Prince Yamabe was appointed as the new Crown Prince.
There is a perspective that emphasizes the political maneuvers of Fujiwara no Momokawa and others in the downfall of Empress Inoe and Prince Osabe.
However, caution is necessary in explaining the details of the incident purely as political intrigue.
It is confirmed that Prince Osabe was removed from the position of Crown Prince, and subsequently, Prince Yamabe became the heir to the throne.
April, 781 (Ten’ō 1).
Upon the abdication of Emperor Kōnin, Prince Yamabe ascended to the throne.
He became known as Emperor Kanmu.
Prince Sawara, Emperor Kanmu’s younger brother, was appointed as Crown Prince.
3. The Incident of Hikami no Kawatsugu in 782
The year following Emperor Kanmu’s accession.
In 782 (Enryaku 1), the Hikami no Kawatsugu Incident occurred.
Hikami no Kawatsugu was the son of Prince Shioyaki and Princess Fuhashi, a daughter of Emperor Shōmu.
Kawatsugu’s retainer, Yamato no Otoko, entered the palace armed and without permission, and was apprehended.
Otoko testified that Kawatsugu was gathering people to attack the court from the north gate.
Although Kawatsugu fled, he was captured in Yamato Province and exiled to Mishima in Izu Province.
Thirty-five individuals, including Fujiwara no Hamanari and Ōtomo no Yakamochi, who were questioned about their connections to Kawatsugu, were also punished.
However, it remains unclear how far Kawatsugu had progressed in his concrete plans for rebellion.
Some interpretations of this incident emphasize the political machinations of the Fujiwara Shikike concerning imperial succession.
From the very beginning of Emperor Kanmu’s reign, the situation surrounding the throne and government was not stable.
A few years later, Emperor Kanmu decided to leave Heijō-kyō.
4. 784: From Heijō-kyō to Nagaoka-kyō
May, 784 (Enryaku 3).
Fujiwara no Oguramaro and Fujiwara no Tanetsugu surveyed the area around Nagaoka Village in Otokuni District, Yamashiro Province, as a candidate for the new capital.
On June 10, Tanetsugu and others were appointed as officials for the construction of Nagaoka Palace, and the building of the capital and palace began.
Then, on November 11.
Emperor Kanmu moved to Nagaoka-kyō.
The relocation to Nagaoka-kyō is sometimes explained as an effort to distance from the powerful temples in Nara.
While the relationship with the Buddhist forces in Nara cannot be ignored, it alone does not fully explain the relocation.
The location of Nagaoka was close to the Yodo River system, offering high convenience for both water and land transportation.
In 787, an edict was issued stating that the capital was placed in Nagaoka due to its advantageous water and land transportation.
While creating a new political center, a large number of people and resources were invested in the construction of Nagaoka-kyō.
However, the year following the relocation, an event occurred that shook the construction of the capital.
5. 785: The Assassination of Fujiwara no Tanetsugu and Prince Sawara
Night of September 23, 785 (Enryaku 4).
Fujiwara no Tanetsugu, a central figure in the construction of Nagaoka-kyō, was shot with an arrow at the construction site.
Tanetsugu died the following day, on the 24th.
Following the investigation, Otomo no Tsuguhito and others were executed, and Crown Prince Sawara was also implicated and punished.
On September 28, Crown Prince Sawara was confined to Otsukuri Temple.
Subsequently, he was deposed and died while being transferred to Awaji Province.
It remains unclear to what extent Crown Prince Sawara was actually involved in the assassination plot.
After his death, Emperor Kanmu’s court experienced a series of misfortunes, including the deaths of imperial family members, outbreaks of disease, and the illness of Crown Prince Anen.
In the 11th year of Enryaku (792).
Divination attributed Crown Prince Anen’s illness to the vengeful spirit of Crown Prince Sawara, prompting the court to send envoys to Awaji to appease his spirit.
That same year, heavy rains and floods struck the area around Nagaoka-kyo.
In later generations, the relocation from Nagaoka-kyo to Heian-kyo was said to be due to fears of Crown Prince Sawara’s vengeful spirit.
It is evident that the court at the time was highly conscious of the curse of Crown Prince Sawara.
However, the move to Heian-kyo was likely influenced by multiple factors, including flooding, the burden of construction, and political circumstances.
Construction at Nagaoka-kyo continued until just before 794, indicating it was not intended as a temporary capital from the start.
6. The Year 789—Defeat in the Campaign Against the Emishi
One of Emperor Kanmu’s key policies was military expansion into the northeast.
Tensions had persisted in Mutsu since the era of Emperor Konin, and in the 11th year of Hoki (780), Tagajo was attacked during the rebellion led by Korehari no Azamaro.
Emperor Kanmu dispatched a large expeditionary force to the northeast.
In the 8th year of Enryaku (789).
General Ki no Kosami’s forces advanced towards the Isawa region.
However, the Emishi along the Kitakami River fiercely resisted.
One of the central figures in this resistance was Aterui.
The government forces suffered significant losses, and the campaign ended in failure. Aterui is recorded as a key figure who dealt a major blow to the imperial forces in this battle.
Historical records note the large numbers of troops mobilized and the extent of the losses.
However, caution is advised when interpreting these figures as the actual numbers of participants on the battlefield.
The crucial point is that the military actions in the early Kanmu era were not easily successful, and the resistance centered around Isawa by the Emishi was strong.
Nevertheless, Emperor Kanmu continued the campaigns.
Subsequently, a key figure on the front lines was Sakanoue no Tamuramaro.
7. Sakanoue no Tamuramaro—To Isawa in 801
Sakanoue no Tamuramaro joined the northeastern military campaign as Deputy Commander in 791 and became the Seii Taishogun in 797.
Year 801 of the Enryaku era.
Once again, Tamuramaro led his forces to the northeast, advancing the government’s control towards the Isawa area.
The following year, 802.
Aterui and More, along with over 500 others, surrendered to Tamuramaro.
The two were sent to the capital, where Tamuramaro is said to have pleaded for their lives.
However, his request was denied, and in August of the same year, Aterui and More were executed in Kawachi Province.
In that same year of 802, construction of Isawa Castle progressed, which later became a crucial political and military hub for managing the northeast.
By the following year, 803, construction of Shiwa Castle further north also began.
However, this did not mark the complete end of resistance in the northeast.
It is appropriate to view this as a significant expansion of the court’s control northward during the Kanmu era.
8. 792 & 797 — Reforming the Military and Local Administration
Emperor Kanmu’s policies were not limited to relocating the capital and subjugating the Emishi.
Year 792 of the Enryaku era.
Except for key frontier provinces like Mutsu, Dewa, Sado, and Saikaido, the traditional military and soldier system was abolished.
Subsequently, a new system was established where young men, primarily the sons of district officials, were selected to guard provincial capitals and armories.
Under the Ritsuryo system, the military system that broadly conscripted farmers was significantly restructured during this period.
In the 16th year of Enryaku (797), the Kageyushi was established.
This was an extra-legal office to oversee the handover when provincial governors changed, examining the handover documents. On September 4, both the chief and assistant officials were appointed simultaneously, marking 797 as the general founding period.
Additionally, policies were implemented to promote land distribution, reduce interest rates on loans, and lessen the burden of corvée labor.
During the Kanmu era, efforts were made not only to maintain the existing Ritsuryo system but also to adapt local administration and military systems to current realities.
Meanwhile, the construction of Nagaoka and Heian capitals and the subjugation of the Emishi required a vast amount of manpower and resources.
These two national projects eventually led to the Tokusei debate in 805.
9. 794 — To Heian-kyo
January of the 12th year of Enryaku (793).
Senior Minister Fujiwara no Oguramaru and others conducted a field survey in the Uda area of Kadono District, Yamashiro Province.
This marked the beginning of the full-scale construction of a new capital.
On October 22, in the 13th year of Enryaku (794).
Emperor Kanmu moved from Nagaoka-kyo to the new capital.
On October 28, an edict for the relocation of the capital was issued, and on November 8, the new capital was named “Heian-kyo.”
Simultaneously, “Yamashiro Province” was renamed “Yamashiro Province.”
However, by October 794, Heian-kyo was not yet fully completed.
Construction of the palace, roads, and government offices continued thereafter.
The office responsible for the construction of Heian-kyo was abolished in December 805.
During his reign, Emperor Kanmu relocated the capital twice.
From Heijo-kyo to Nagaoka-kyo.
From Nagaoka-kyo to Heian-kyo.
This marked the beginning of the capital that would later become Kyoto.
10. The Year 804—Saicho and Kukai Travel to Tang China
The 23rd year of Enryaku (804).
An envoy set out for Tang China.
Among the group were two monks.
They were Saicho and Kukai.
Saicho had been training on Mount Hiei and, upon receiving permission to travel to Tang, studied Tendai teachings and esoteric Buddhism.
He departed in July 804 and returned to Japan in 805.
Meanwhile, Kukai remained in Tang to study esoteric Buddhism, returning in 806.
Emperor Kanmu passed away before seeing their return.
The Buddhist knowledge gained from this mission greatly influenced Japanese Buddhism after Emperor Kanmu’s death.
The Kanmu era was a period that connected to the next era not only in politics, military, and urban development but also in religion.
11. The Year 805—Reevaluation of “Military Affairs” and “Construction”
The 24th year of Enryaku (805), December.
Emperor Kanmu had Sangi Fujiwara no Otsugu and Sugano no Mamichi discuss the governance of the realm.
This discussion later became known as the Tokusei Dispute.
Otsugu pointed out “military affairs” and “construction” as burdens on the people and called for their cessation.
Military affairs referred to the subjugation of the Emishi.
Construction referred to the building of Heian Palace and Heian-kyo.
On the other hand, Sugano no Mamichi, who had long been involved in palace construction, opposed Otsugu.
Emperor Kanmu adopted Otsugu’s opinion.
During the Kanmu era, the construction of the capital and the subjugation of the Emishi had been ongoing for many years.
Otsugu sought to halt these two state projects due to the burden on the people, and Emperor Kanmu accepted this argument.
The construction of Heian-kyo and the subjugation of the Emishi were hallmark policies of Emperor Kanmu’s reign.
However, their realization required significant manpower and state expenditure.
The decision in 805 indicates that these two longstanding state projects were reevaluated in the final years of the Kanmu era.
12. The Year 806—The Death of Emperor Kanmu
The 25th year of Enryaku (806), March 17.
Emperor Kanmu passed away.
He was said to be 70 years old.
Kashiwabara Mausoleum, located in present-day Fushimi Ward, Kyoto City, is designated as his tomb.
Born as Prince Yamabe in 737, his path to the throne was not assured from the beginning.
He became Crown Prince after the deposition of Prince Osabe and ascended the throne in 781.
In the following 25 years, he moved the capital from Heijo-kyo to Nagaoka-kyo, and then to Heian-kyo.
In the northeast, despite experiencing the defeat of Ki no Kosami’s army, he continued military campaigns and extended the court’s control to the Isawa region under Sakanoue no Tamuramaro.
He reformed the military and soldier system, established the Kageyushi to strengthen oversight of local administration, and in 804, dispatched an envoy to Tang China.
Then, in the final year of his life, 805.
When Fujiwara no Otsugu called for the cessation of “military affairs” and “construction projects,” he adopted this advice.
The politics of Emperor Kanmu were not about unwaveringly sticking to a single policy until the end.
While he advanced large-scale city-building and military actions, he also reformed the military system and local administration, and by the end of his reign, he re-evaluated the very state projects he had long pursued.
After Emperor Kanmu’s death, some of his sons and grandsons were given the Taira surname.
Among them, from the lineage of Prince Kazurahara, emerged Prince Takamochi, who would later lead to the Kanmu Taira clan.
However, this is a history that unfolded after the time of Emperor Kanmu himself.
In Emperor Kanmu’s life, which ended in 806, a significant achievement was his reorganization of the Ritsuryo state inherited from the Nara period, including the capital, military system, local administration, northeastern policy, and foreign relations.
The Heian-kyo, constructed during his reign, would continue to serve as Japan’s capital for many years to come.
📚 For Those Who Want to Know More About Emperor Kanmu
In this article, we followed the life of Emperor Kanmu through the lenses of Heian-kyo, the subjugation of the Emishi, military reforms, and the Kanmu Taira clan.
For those who wish to delve deeper, **’Emperor Kanmu: The Emperor Destined for City-Building and Subjugation’** is recommended.
It offers a deeper understanding of the two colossal projects of city-building and subjugation that lay behind the image of “the emperor who built Heian-kyo.”
Emperor Kanmu: The Emperor Destined for City-Building and Subjugation (Japanese History Libretto) [ Masahiro Nishimoto ]
🍡 After Learning History, Enjoy Kyoto’s Sweets
The Heian-kyo built by Emperor Kanmu in 794.
There is also a Kyoto confectionery assortment named **”Heian”** that carries on that name.
Enjoying Kyoto-style sweets like yatsuhashi, warabi mochi, and yokan while reflecting on the era when the name “Heian-kyo” was born might be an interesting experience.
