On September 6, 810, Emperor Heizei issued an order to move the capital back from Heian-kyo to Heijo-kyo.
It had been 16 years since Emperor Kanmu had relocated the capital to Heian-kyo.
By this time, his younger brother, Emperor Saga, had ascended the throne and was conducting state affairs in Heian-kyo.
Initially, Emperor Saga accepted the retired emperor’s command and appointed Sakanoue no Tamuramaro and Fujiwara no Nakanari to oversee the refurbishment of Heijo Palace.
On September 10, Emperor Saga fortified the provincial offices and old checkpoints in Ise, Omi, and Mino, and detained Fujiwara no Nakanari. Fujiwara no Kusuko was also stripped of her official rank.
The following day, on September 11, Emperor Heizei departed Heijo-kyo with Kusuko and others, heading east.
Emperor Saga dispatched Sakanoue no Tamuramaro.
Emperor Heizei’s party was unable to leave Yamato Province and returned the next day, on September 12.
The retired emperor took religious vows, and Kusuko took her own life.
This was the Incident of Kusuko, a conflict between the two sons of Emperor Kanmu: Emperor Heizei and Emperor Saga.
Prince Ate, Son of Emperor Kanmu
Prince Ate, who would later become Emperor Heizei, was born in the fifth year of Hoki (774).
His father was Emperor Kanmu, and his mother was Fujiwara no Otomuro.
His younger brother by the same mother was Prince Kamino, who would later become Emperor Saga.
In the fourth year of Enryaku (785), when Crown Prince Sawara was deposed, Prince Ate became the crown prince.
That same year, Fujiwara no Tanetsugu, a key figure in the construction of Nagaoka-kyo, was assassinated.
Fujiwara no Kusuko was Tanetsugu’s daughter.
Fujiwara no Kusuko and Prince Ate
Kusuko’s birth year is not recorded.
She was born the daughter of Fujiwara no Tanetsugu of the Fujiwara Shikike, and became the wife of Fujiwara no Nawa no Aruji.
When her daughter by Nawa no Aruji entered the Crown Prince Ate’s palace, Kusuko also began serving there.
Eventually, Prince Ate and Kusuko developed a deep relationship.
According to a fragment from the “Nihon Koki,” Emperor Kanmu viewed their relationship as problematic and removed Kusuko from the palace.
Kusuko had a brother named Fujiwara no Nakanari.
Nakanari was born in the eighth year of Tenpyo-hoji (764), the same child of Fujiwara no Tanetsugu as Kusuko.
He would later work closely with Kusuko near Emperor Heizei.
The Year 806: Emperor Heizei’s Ascension
On March 17, in the 25th year of Enryaku (806), Emperor Kanmu passed away.
Crown Prince Ate ascended the throne.
He became Emperor Heizei.
He was 33 years old by count.
Yakushi, who had been removed from the crown prince’s side by Emperor Kanmu, returned once more to the emperor’s proximity.
Yakushi became the Naishi no Kami and rose to the junior third rank.
The Naishi no Kami was the head of the Naishi Bureau, responsible for conveying petitions to the emperor and transmitting the emperor’s orders.
Her brother, Nakanari, also advanced in rank during Heizei’s reign. In the fourth year of Daido (809), he became the inspector of the Hokuriku region.
Emperor Heizei’s reign lasted only three years.
In 809, Abdication to His Younger Brother, Prince Kamino
In the fourth year of Daido (809), Emperor Heizei was suffering from illness.
On April 1, he abdicated the throne to his younger brother, Prince Kamino.
This marked the accession of Emperor Saga.
Emperor Heizei became the retired emperor, and his son, Prince Takaoka, was appointed crown prince.
Even after abdication, the retired Emperor Heizei’s health remained unstable, and he continued to move residences for recuperation.
In December of the same year, the retired emperor entered the old capital of Heijokyo.
Yakushi and Nakanari were also present around the retired emperor.
While Emperor Saga conducted affairs of state in Heian-kyo, the retired Emperor Heizei, who had moved to Heijokyo, continued to involve himself in politics.
The following year, 810, this involvement extended to the very institutions of the court.
March 810, Emperor Saga Establishes the Kurando
In March of the fifth year of Daido (810).
Emperor Saga appointed Kose no Notari and Fujiwara no Fuyutsugu as heads of the Kurando.
This marked the beginning of the Kurando-dokoro.
The Kurando handled confidential documents close to the emperor and were involved in transmitting the emperor’s orders.
Amid rising tensions with the retired Emperor Heizei’s faction, a system for maintaining confidentiality and transmitting orders directly under Emperor Saga was being established.
Fujiwara no Fuyutsugu hailed from the Northern Fujiwara family.
Though he was still around 30 years old at this time, he advanced into the central administration as a close aide to Emperor Saga.
June, the Retired Emperor Heizei Abolishes the Inspectors
In June of the fifth year of Daido.
The retired Emperor Heizei ordered the abolition of the inspectors and the restoration of the councilors.
The inspectors were a system established by Emperor Heizei during his reign, responsible for overseeing local administration.
It was the retired emperor himself who issued an order to revise a system he had established during his own rule.
The councilors were reinstated, and Fujiwara no Nakanari was appointed as a councilor.
The retired Emperor Heizei’s involvement in politics continued, and by September, orders were issued to move the capital itself.
September 6, Orders to Move the Capital Back to Heijokyo
On September 6 of the fifth year of Daido.
The retired Emperor Heizei ordered the abolition of Heian-kyo and the return of the capital to Heijokyo.
Emperor Kanmu had moved the capital from Nagaokakyo to Heian-kyo in the 13th year of Enryaku (794).
Only 16 years had passed since then.
In response to the retired emperor’s order, Emperor Saga’s side began preparations to restore Heijo Palace.
Sakanoue no Tamuramaro and Fujiwara no Nakanari were appointed as officials in charge of palace construction.
Officials and the public were also required to prepare for the move to Heijo-kyo, as the imperial court began to take steps towards the relocation.
This situation did not last long.
On September 10, Emperor Saga took action to suppress the forces of the retired Emperor.
September 10: Securing Ise, Omi, and Mino
On the 10th day of the 9th month of Daido 5.
Emperor Saga sent envoys to Ise, Omi, and Mino, securing the provincial capitals and old checkpoints of these three regions.
These areas were located along the routes leading from Heian-kyo and Heijo-kyo to the eastern provinces.
At the same time, actions were taken against officials aligned with the retired Emperor Heijo.
Fujiwara no Nakanari was captured and detained at the Right Division of the Imperial Guards.
He was demoted from Councilor to Deputy Governor of Sado.
Yakushi was also stripped of her court rank and banned from entering the palace.
Emperor Saga issued an edict outlining the crimes of Yakushi and Nakanari.
The order to move the capital to Heijo-kyo, issued on September 6, was also halted.
The following morning, the retired Emperor Heijo left Heijo-kyo.
September 11: The Retired Emperor Heijo Heads East
Early on the morning of September 11.
The retired Emperor Heijo, accompanied by Yakushi and others, departed from Heijo-kyo.
Their destination was the eastern provinces.
Emperor Saga dispatched Sakanoue no Tamuramaro.
Tamuramaro had been appointed as the Seii Taishogun in the 16th year of Enryaku (797) and had led campaigns against the Emishi in 801.
He was involved in the construction of Fort Isawa in 802 and Fort Shiwa in 803.
By 810, he held the position of Dainagon at the heart of the imperial court.
As Tamuramaro prepared to head east, he requested to bring along a certain individual.
This was Bun’ya no Watamaro.
Watamaro had been suspected of having ties with the retired Emperor Heijo’s side and was detained, but was allowed to accompany Tamuramaro upon his request.
On the same day, September 11, the execution of Fujiwara no Nakanari took place in Heian-kyo.
The Execution of Fujiwara no Nakanari
Fujiwara no Nakanari, who had been detained at the Right Division of the Imperial Guards, was executed by shooting.
He had just been demoted from Councilor to Deputy Governor of Sado the previous day.
Nakanari was believed to have been born in the 8th year of Tenpyō Hōji (764), making him 47 years old by traditional counting.
Alongside his sister Yakushi, he was involved in politics close to the retired Emperor Heijo and lost his life amid the political upheaval.
Meanwhile, the entourage of the retired Emperor Heijo continued their journey eastward.
Emperor Saga’s forces had already secured the regions of Ise, Omi, and Mino.
The retired Emperor’s party was unable to leave Yamato Province.
September 12: The Retired Emperor Heijo Turns Back
On September 12.
The party of the retired Emperor Heijo advanced as far as Koshi Village in Soekami District, Yamato Province.
They abandoned the advance and retreated to Heijo-kyo.
The retired emperor shaved his head and became a monk.
Yakushi took poison and ended her own life.
This occurred six days after the order to move the capital back to Heijo-kyo was issued on September 6.
The retired Emperor Heijo continued to live in Heijo-kyo thereafter.
The resolution of the political upheaval also affected the retired emperor’s son.
Prince Takaoka Removed as Crown Prince
Prince Takaoka, son of the retired Emperor Heijo, was removed from his position as crown prince.
In his place, Prince Otomo was appointed as the new crown prince.
Prince Otomo was a son of Emperor Kanmu and a half-brother to both the retired Emperor Heijo and Emperor Saga.
He would later become Emperor Junna.
Afterward, Prince Takaoka became a monk and became a disciple of Kukai.
The retired Emperor Heijo continued to live in Heijo-kyo after the political upheaval and passed away at the age of 51 in the 15th year of the Konin era (824).
Under Emperor Saga, Fujiwara no Fuyutsugu, who served as the head of the Kurando-dokoro, rose to the position of councilor, and the Fujiwara Northern House expanded its influence at the court.
September 19: Era Name Changed to “Konin”
Seven days after the resolution of the Yakushi Incident, on September 19.
The era name was changed from “Daido” to “Konin.”
Thus, the key events of the political upheaval, including the order to move the capital to Heijo-kyo, the arrest and execution of Nakanari, the eastward journey of the retired Emperor Heijo, and the death of Yakushi, all occurred in the 5th year of the Daido era (810).
On May 23 of the following year, the 2nd year of the Konin era (811), Sakanoue no Tamuramaro passed away at the age of 54.
In the same year, Bun’ya no Watamaro, who had acted alongside Tamuramaro during the previous year’s political upheaval, was appointed as the Seii Taishogun and advanced the army towards the Nissatsu and Hei areas.
From September 6, 810, when the retired Emperor Heijo ordered the capital to be moved to Heijo-kyo, to September 12, when he abandoned the eastward journey and became a monk, was a span of six days.
The capital did not return from Heian-kyo to Heijo-kyo, and Emperor Saga continued to govern from Heian-kyo.
📚 For those who want to learn more about the Yakushi Incident
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The “Heijokyo” where Emperor Heizei returned.
This area, now known as Nara City, became the stage for a conflict that eventually escalated into armed confrontation with Emperor Saga.
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