November, 643 AD, the second year of Empress Kōgyoku’s reign.
In Ikaruga, Yamato Province, forces dispatched by Soga no Iruka advanced.
Their target was Prince Yamashiro no Ōe.
He was the son of Prince Shōtoku and had once been a prominent contender for the throne alongside Prince Tamura.
Prince Yamashiro no Ōe’s side resisted.
Mitsunari, leading several dozen retainers, fought back and shot down Haji no Saba, a commander on Iruka’s side, with an arrow. The battle was fierce enough to cause the attacking forces to retreat in fear.
Taking advantage of this opportunity, Prince Yamashiro no Ōe escaped Ikaruga Palace with his family and fled to Mount Ikoma.
His retainers advised him to head to the eastern provinces to gather troops for a counterattack.
Although Prince Yamashiro no Ōe acknowledged the possibility of victory, he chose not to pursue this course.
A few days later, the prince returned to Ikaruga on his own.
At Ikaruga Temple, he took his own life along with his children and consorts.
The royal family of Prince Shōtoku suffered a significant blow.
Why did Soga no Iruka drive Prince Yamashiro no Ōe to such extremes?
Tracing the background reveals a political struggle over succession that had persisted for 15 years since the death of Empress Suiko.
Prince Shōtoku’s Son—Prince Yamashiro no Ōe
Prince Yamashiro no Ōe was born as the son of Prince Shōtoku.
His mother was Tojiko no Iratsume.
She was the daughter of Soga no Umako.
On his father’s side, he was the grandson of Emperor Yōmei, and on his mother’s side, he was also the grandson of Soga no Umako.
He possessed a noble lineage as a member of the imperial family and had deep familial ties with the powerful Soga clan of the time.
In 622, his father, Prince Shōtoku, passed away.
In 626, Soga no Umako also died, and his son Soga no Emishi took over as the head of the Soga clan.
Then, in March 628, Empress Suiko passed away.
At that time, no successor to the throne had been decided.
Two prominent candidates emerged: Prince Tamura and Prince Yamashiro no Oe.
628—Prince Tamura or Prince Yamashiro no Oe
Prince Tamura was the grandson of Emperor Bidatsu and the son of Prince Oshisaka no Hikohito no Oe.
He would later become Emperor Jomei.
On the other hand, Prince Yamashiro no Oe was the grandson of Emperor Yomei and the son of Prince Umayado.
According to the Nihon Shoki, the ailing Empress Suiko summoned both Prince Tamura and Prince Yamashiro no Oe to her bedside shortly before her death, leaving them with parting words.
To Prince Tamura, she advised that ruling the realm should not be taken lightly and urged him to consider carefully.
To Prince Yamashiro no Oe, she advised him not to act rashly on his own thoughts and to heed the counsel of the ministers.
How these words were interpreted became a point of contention thereafter.
Even by September, after Empress Suiko’s funeral, a successor had not been decided.
Soga no Emishi, a powerful minister, gathered the court officials to seek their opinions on who should become the next sovereign.
Otomo no Kujira and others supported Prince Tamura.
Meanwhile, Kose no Omi Maro, Saeki no Atai Hito, and Ki no Shiotetsu supported Prince Yamashiro no Oe.
The court was divided in its opinion.
Even within the Soga clan, there was division, as Sakaibe no Marise, Emishi’s uncle, supported Prince Yamashiro no Oe.
The issue of imperial succession thus escalated into an internal conflict within the Soga clan.
The Death of Sakaibe no Marise
Sakaibe no Marise had long communicated his support for Prince Yamashiro no Oe as the next sovereign to Emishi.
The conflict with Emishi, who leaned towards supporting Prince Tamura, gradually intensified.
Marise eventually aligned himself with the faction supporting Prince Yamashiro no Oe.
The Nihon Shoki records an instance where Prince Yamashiro no Oe himself advised Marise to avoid causing chaos for the sake of one person.
Nevertheless, the conflict between the two factions did not subside.
Emishi dispatched troops and had Marise killed.
Subsequently, in January 629, Prince Tamura ascended the throne.
He became Emperor Jomei.
Prince Yamashiro no Oe did not ascend to the throne.
However, the family of Prince Umayado remained in Ikaruga, and Prince Yamashiro no Oe continued to exist as a prominent member of the imperial family.
Then, in 641, Emperor Jomei passed away.
The situation surrounding the imperial succession began to shift once more.
The Accession of Empress Kogyoku—The Rise of Soga no Iruka
After Emperor Jomei’s death, in 642, Princess Takara ascended the throne.
She became Empress Kogyoku.
During this period, Soga no Iruka, the son of Soga no Emishi, began to take a leading role in the politics of the Soga clan.
Meanwhile, within the imperial family, there was Prince Furubito no Oe.
Prince Furubito no Oe was the son of Emperor Jomei, and his mother, Hotei no Iratsume, was the daughter of Soga no Umako.
Prince Yamashiro no Oe was also a grandson of Soga no Umako.
Prince Furubito no Oe was likewise a grandson of Soga no Umako.
Both were of imperial lineage and had deep ties with the Soga clan.
The Nihon Shoki notes that during this period, Iruka was highly wary of the growing reputation of the Uemiya royal family throughout the land.
Then, in the second year of Empress Kōgyoku’s reign, 643.
Iruka finally resorted to military force to eliminate them.
November 643—Iruka Sends Troops to Ikaruga
The November entry for the second year of Empress Kōgyoku in the Nihon Shoki provides a detailed account of the assault.
Soga no Iruka dispatched Shotoku, Kose no Tokuta no Omi, and Daini, Haji no Saba no Muraji, to attack Prince Yamashiro no Ōe and others in Ikaruga.
Another account mentions that Kose no Tokuta no Omi and Yamato no Makai no Kubi were appointed as generals.
The forces advanced on Ikaruga.
Prince Yamashiro no Ōe’s side was not merely besieged.
Mitsunari, who served the prince, led several dozen retainers to counter the attack.
“One Against a Thousand”—Mitsunari’s Resistance
The battle commenced in Ikaruga.
Mitsunari and several dozen retainers on Prince Yamashiro no Ōe’s side faced off against Iruka’s forces.
In this battle, Haji no Saba no Muraji was struck by an arrow and killed.
With the loss of one of their commanders, the troops were frightened and withdrew.
The Nihon Shoki records that the soldiers spoke of Mitsunari,
“One Against a Thousand”
meaning he was a warrior capable of facing a thousand men alone.
Prince Yamashiro no Ōe took this opportunity to escape from Ikaruga Palace.
The prince placed a horse’s bones in the sleeping quarters.
Then, taking his consort and children, he seized the chance to slip out of the palace.
They headed towards Mount Ikoma.
The Burning of Ikaruga Palace—The Pursuers Deceived by Horse Bones
After Prince Yamashiro no Ōe’s escape, Kose no Tokuta no Omi and others set Ikaruga Palace ablaze.
The palace was engulfed in flames.
Soon, the soldiers found bones amidst the ashes.
These were the horse bones left by Prince Yamashiro no Ōe in the sleeping quarters.
The pursuing forces mistook them for the prince’s remains and concluded that Prince Yamashiro no Ōe had perished.
They lifted the siege and retreated.
Meanwhile, Prince Yamashiro no Ōe was hiding on Mount Ikoma with his family and close aides.
The Nihon Shoki names those accompanying him as Miwa no Fumiya no Kimi, Toneri no Tamura no Muraji and his daughter, Uda no Moroishi, and Ise no Abe no Katatsune.
Four to Five Days on Mount Ikoma—Food Supplies Exhausted
Prince Yamashiro no Ōe and his group hid on Mount Ikoma.
They remained there for four to five days.
The Nihon Shoki records that during this time, they were unable to find anything to eat.
In a dire situation, he was forced to hide in the mountains.
It was then that Miwa no Fumiyakimi advised Prince Yamashiro no Oe to make a comeback.
First, they would head to Fukakusa Tonokura.
From there, they would ride horses to the eastern provinces.
By rallying forces based on the support in the eastern provinces, they would return to fight against Iruka.
Fumiyakimi argued that this plan would surely lead to victory.
Even Prince Yamashiro no Oe did not dismiss the possibility of success.
However, the prince chose not to fight.
“I do not wish to cause suffering to the people for my sake alone”
The words of Prince Yamashiro no Oe, as recorded in the Nihon Shoki, are particularly memorable in this event.
Executing Miwa no Fumiyakimi’s plan would likely lead to victory in battle.
Prince Yamashiro no Oe acknowledged this.
Yet, he expressed his desire not to cause suffering to the people for his own sake.
He did not wish for future generations to say,
“I lost my parents because of that prince.”
He did not desire such a battle.
Is fighting and winning the only way to be a noble man?
Is sacrificing oneself for the stability of the nation not also a noble act?
The Nihon Shoki conveys that Prince Yamashiro no Oe abandoned the idea of raising an army due to such beliefs.
He closed off the path of fleeing to the eastern provinces to regroup.
However, Iruka’s side also became aware that Prince Yamashiro no Oe was still alive.
Iruka Learns of Prince Yamashiro no Oe’s Survival
There were those who had seen Prince Yamashiro no Oe and his followers in the mountains.
This information reached Iruka.
According to the Nihon Shoki, upon learning that Prince Yamashiro no Oe was alive, Iruka was “greatly alarmed” and quickly mobilized his troops.
Iruka ordered Takamukai no Kuni Oshi to head to the mountains and capture the prince.
Kuni Oshi refused, stating that he could not leave as he was guarding the imperial palace.
Thus, Iruka decided to go to the mountains himself.
At that moment, Prince Furubito no Oe appeared.
Prince Furubito no Oe asked Iruka where he was headed and inquired about the situation.
Then, he imparted words to the effect of,
“A mouse hides in its hole to live, and dies if it loses its hole.”
Iruka decided against going to the mountains himself and sent his forces to Ikoma instead.
Even then, they could not find Prince Yamashiro no Oe.
Subsequently, Prince Yamashiro no Oe descended from the mountains on his own.
He headed towards Ikaruga.
Prince Yamashiro no Oe Returns to Ikaruga Temple
Prince Yamashiro no Oe, having left Mount Ikoma, entered Ikaruga Temple.
This is the Ikaruga Temple mentioned in the Nihon Shoki, a temple established by Prince Shotoku, which is connected to the present-day Horyu-ji Temple. The old temple complex is thought to be related to the Wakakusa Temple ruins remaining southeast of the current Western Precinct.
Forces loyal to Iruka surrounded the temple.
At this point, Prince Yamashiro no Oe conveyed his intentions to the military commanders through Miwa no Fumiya no Kimi.
If I raise an army and attack Iruka, I can win.
However, I do not wish to harm the people for my own sake.
Therefore, I will surrender myself to Iruka.
Then, Prince Yamashiro no Oe took his own life along with his children, wives, and concubines.
This occurred in the 11th month of the second year of Empress Kogyoku’s reign (643 AD).
The Fall of the Ue no Miya Royal Family
The death of Prince Yamashiro no Oe dealt a significant blow to the Ue no Miya royal family, descendants of Prince Umayado.
Following the account of their deaths, the Nihon Shoki describes a mysterious phenomenon where five-colored banners and canopies, along with various performances, appeared in the sky, covering the temple.
This is a narrative depiction included in the Nihon Shoki.
The news also reached Iruka’s father, Soga no Emishi.
Emishi’s reaction was intense.
“Your Life is in Danger Too” — Soga no Emishi Rebukes Iruka
Upon hearing that Prince Yamashiro no Oe and others were destroyed by Iruka, Soga no Emishi reprimanded his son.
In the Nihon Shoki,
“Alas, Iruka, you are extremely foolish and have acted with reckless violence,”
it is recorded.
Iruka, you are too foolish, acting with reckless violence on your own.
Furthermore,
“Isn’t your own life also in danger?”
he warned.
This scene is significant.
The Nihon Shoki portrays the attack on Prince Yamashiro no Oe as Iruka’s own action, with his father Emishi harshly criticizing the outcome.
It was not a simple case of the Soga clan uniting to destroy Prince Shotoku‘s lineage.
Within the same Soga clan, in 628, Sakaibe no Marise and Emishi clashed over the imperial succession, and in 643, Emishi rebuked Iruka’s actions.
There were political differences within the Soga clan itself.
Why Did Iruka Destroy Prince Yamashiro no Oe?
The Nihon Shoki notes that just before the attack, Iruka was deeply wary of the growing fame of the “Ue no Miya Princes” throughout the land.
Prince Yamashiro no Oe was not merely the orphan of Prince Umayado.
In the imperial succession dispute of 628, multiple court officials actually supported him as the next candidate for the throne.
Sakaibe no Marise, a prominent member of the Soga clan, also backed Prince Yamashiro no Oe.
Even after Prince Tamura ascended the throne as Emperor Jomei, Prince Yamashiro no Oe continued to live, based in Ikaruga.
By 643, he remained a significant figure in considerations of imperial succession.
However, when examining why Iruka sought to eliminate Prince Yamashiro no Oe, it is necessary to consider the critical portrayal of Iruka in the “Nihon Shoki,” which depicts him as being destroyed in the Isshi Incident.
What is clear from historical records is that Iruka was wary of the fame of Prince Yamashiro no Oe and others, and in November 643, he sent troops, leading to the downfall of the Uemiya royal family.
Two Years After the Death of Prince Yamashiro no Oe—The Isshi Incident
About one year and seven months after the fall of Prince Yamashiro no Oe’s family.
On June 12, in the fourth year of Empress Kogyoku’s reign (645), a significant event occurred at the Asuka Itabuki Palace.
Soga no Iruka was assassinated in the palace by Prince Naka no Oe and Nakatomi no Kamatari.
This was the Isshi Incident.
The following day, his father, Soga no Emishi, set fire to his own residence and committed suicide.
November 643.
In Ikaruga, where Iruka had sent his forces, Prince Yamashiro no Oe rejected the path to rebuild in the eastern provinces and met his end with his family.
June 645.
Now it was Iruka who was attacked in the Asuka palace.
The conflict over imperial succession and power that had persisted since the death of Empress Suiko, culminating in the attack on Prince Yamashiro no Oe, eventually led to the Isshi Incident.
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