In the middle of the 7th century, Japan was not a unified nation but a patchwork of powerful, semi-autonomous clans, or uji. At the center of this web, the Yamato imperial family held symbolic and religious authority, but real political power was often wielded by the strongest of these aristocratic clans. By 645 CE, one clan—the Soga—had become so dominant that they threatened to eclipse the imperial line itself. It was in this tense atmosphere that a bloody coup would trigger a seismic shift, a top-down revolution known as the Taika Reforms, which would forever alter the course of Japanese history.

The Stage for Revolution: The Soga Clan’s Grip

For decades, the Soga clan had expertly navigated the complex politics of the Asuka period court. Through strategic marriages into the imperial family, they had become the power behind the throne, controlling state finances and influencing—and at times, dictating—the imperial succession. They were champions of Buddhism, using the new religion to bolster their prestige and build magnificent temples that showcased their wealth and influence.

By the 640s, however, their ambition had grown into outright arrogance. The clan head, Soga no Iruka, ruled with an iron fist. He had his rival, Prince Yamashiro, and his family forced to commit suicide to clear the path for his own preferred imperial candidate. Iruka and his father, Emishi, built lavish palaces and tombs for themselves, adopting symbols and titles traditionally reserved for royalty. To many, it seemed the Soga were no longer content to be kingmakers; they wanted the crown for themselves. This overreach created a powder keg of resentment among other nobles and, most importantly, within a faction of the imperial family itself.

A Coup in the Court: The Isshi Incident

The breaking point came on July 10, 645 CE, in a bloody event known as the Isshi Incident (named after the year in the zodiacal calendar). The chief conspirators were Prince Naka no Ōe, a savvy and determined royal, and his trusted ally, Nakatomi no Kamatari, the head of a rival priestly clan.

The stage was a court ceremony where envoys from Korea were presenting tribute to Empress Kōgyoku. Soga no Iruka, feeling secure in his power, attended unarmed. As a courtier began to read the memorials, Prince Naka no Ōe’s assassins hesitated. In a moment of high drama, the prince himself snatched a spear and charged Iruka. The other assassins, their courage restored, joined the fray. The wounded Iruka pleaded for his life, but the Empress, seeing the coup was already in motion, withdrew. Iruka was summarily executed on the spot.

The next day, Soga no Emishi, seeing his clan’s power evaporate overnight, set fire to his residence and took his own life. The Soga’s decades-long dominance was over. Empress Kōgyoku abdicated in favor of her brother, who became Emperor Kōtoku. Prince Naka no Ōe was named Crown Prince, and Nakatomi no Kamatari was appointed Inner Minister. With the old guard violently swept away, the path was clear to remake Japan from the ground up.

The Tang Model: A Blueprint for a New Japan

The coup was not just about removing the Soga; it was about implementing a radical new vision for the state. For this, Naka no Ōe and his advisors looked abroad to their colossal neighbor: Tang Dynasty China. Japanese missions to the Tang court (kentōshi) had returned with awe-inspiring tales of a vast, centralized empire ruled by a powerful Son of Heaven. They described:

• A sophisticated bureaucracy staffed by scholar-officials.
• A detailed legal and penal code (the lüling, which becomes ritsuryō in Japanese).
• A system of nationalized land (the “equal-field system”) that was distributed to peasants in return for taxes.
• A national census and household registration to manage taxtion and conscription.

To the Japanese reformers, the Tang model was a perfect blueprint for breaking the power of the clans and creating a strong, unified state under the absolute authority of the emperor. It was a vision of order, efficiency, and centralized power.

The Pillars of the Taika Reforms

Beginning in 646 CE, Emperor Kōtoku, guided by Prince Naka no Ōe, issued a series of edicts collectively known as the Taika Reforms (meaning “Great Change”). These edicts were the foundational pillars of the new state and can be summarized in four key policies:

1. Abolition of Private Land and Power

This was the most revolutionary reform. The edict abolished all private land and serfdom held by the aristocratic uji. All land and people were now, in theory, the public property of the emperor. This struck directly at the economic base of the clans, who could no longer draw their power from their vast, privately owned estates.

2. A New Central and Provincial Government

To replace the clan-based administration, Japan was reorganized. A permanent capital was established (first at Naniwa, near modern-day Osaka), with a central government modeled on the Chinese system. The country was divided into provinces (kuni), districts (gun), and townships (ri). Crucially, the emperor, not local clan leaders, would now appoint governors to oversee these provinces, ensuring loyalty to the throne.

3. Census, Household Registers, and Land Allotment

To implement the new system, a national census was ordered. Every household was registered, and based on this data, rice land (paddies) was systematically allotted to cultivators. In return for the right to farm this public land, peasants were obligated to pay taxes to the central government, not a local lord.

4. A Rationalized Tax System

The old, haphazard system of tribute to the clans was replaced with a uniform, national tax system. This included a tax on harvests (usually rice), a tax on other products like silk or cotton (payable in kind), and a corvée labor tax, which could also be commuted to military service. For the first time, a steady stream of revenue flowed directly to the imperial treasury, funding the new government, its officials, and its army.

Legacy and Reality: Forging the Imperial State

The Taika Reforms were a breathtakingly ambitious project. As a top-down revolution, their implementation was uneven and faced resistance. The old aristocratic families, though stripped of他們的 land, did not simply disappear. Nakatomi no Kamatari himself, rewarded with the new surname Fujiwara, founded a clan that would come to dominate court politics for centuries, proving that influence could be wielded in new ways.

Furthermore, the equal-field system, the economic heart of the reforms, began to erode over time. Powerful nobles and Buddhist monasteries渐渐地 able to gain exemptions and build up vast, tax-free private estates (shōen), which slowly starved the central government of revenue and laid the groundwork for a new, feudal-style system.

Despite these challenges, the legacy of the Taika Reforms is undeniable. They successfully shattered the old uji system and established the legal and philosophical principle of the emperor as the absolute sovereign of the state. They laid the foundation for the Ritsuryō state, Japan’s first centralized imperial government, which was fully codified in the Taihō Code of 701. This “Great Change” of 645 CE was the crucible in which ancient Japan was forged, transforming a confederation of warring clans into an aspiring imperial empire and setting the stage for the classical civilizations of Nara and Heian.