Taika Reform

The Taika Reform is the name historians give to a series of political changes in Japan that began with a coup in 645. The word Taika (大化) means “great change” and was the name of the new era proclaimed that year — the first time Japan used era names in the Chinese way. The reforms aimed to replace a system in which great clans held their own land and people with a system in which a single ruler, the tennō (emperor), governed through officials, laws and registers.

Most of what we know comes from the Nihon Shoki (Chronicles of Japan), the court history completed in 720. It describes the coup in dramatic detail and quotes a long Reform Edict said to have been issued on the first day of 646. Because the Chronicles were written seventy years later by the heirs of the reformers, historians have spent a century testing their account against other evidence, especially wooden tablets and the remains of palaces.

The reform did not create a new state overnight. It was the start of a long process that continued through the reigns of Tenji (668–671) and Tenmu (673–686) and was completed with the Taihō Code of 701. But the events of 645 became the traditional starting point of the Japanese imperial state.

In the sixth and early seventh centuries, the Yamato king ruled together with powerful clans (uji). Each clan had hereditary titles, its own lands and groups of dependent workers (be) who produced goods or services for it. The greatest of these clans in the early seventh century was the Soga. Soga leaders had married their daughters into the royal family, championed Buddhism, built Asuka-dera, and dominated the choice of rulers.

Under Empress Suiko (r. 593–628), Soga no Umako shared power with Prince Shōtoku. After their deaths, Umako’s son Emishi and grandson Iruka became even more dominant. In 643 Iruka attacked Prince Yamashiro no Ōe, Shōtoku’s son and a possible heir to the throne, at Ikaruga; Yamashiro and his family died. According to the Chronicles, the Soga were also building grand tombs and residences in a style that looked like royal privilege.

At the same time, students who had gone to China with the embassies of Shōtoku’s time were coming home. They had watched the Sui dynasty fall and the Tang rise, and they knew how a Chinese-style state worked: officials ranked by merit, registers of households, taxes on every adult and land given out by the state. For ambitious young royals, these ideas offered a way to break the Soga.

The conspiracy was led by Prince Naka no Ōe, a son of Empress Kōgyoku, and Nakatomi no Kamatari, a member of a clan of court ritualists. The Chronicles tell a famous story of how they met: at a game of kemari (kickball) at Asuka-dera, the prince’s shoe flew off, and Kamatari picked it up and returned it, beginning their friendship.

On the twelfth day of the sixth month of 645, at the Asuka Itabuki Palace, a ceremony was held in front of the empress in which, according to the Chronicles, tribute from the Korean kingdoms was being presented. The conspirators had arranged for swordsmen to strike; when they hesitated, Naka no Ōe himself attacked Iruka, and the guards finished him. The next day Soga no Emishi set fire to his residence and died. The fire is said to have destroyed royal records, including the histories compiled by Shōtoku and Umako.

Empress Kōgyoku abdicated — the first recorded abdication in Japan. Her brother became Emperor Kōtoku, and Naka no Ōe became crown prince. New ministers were appointed, Kamatari became the chief adviser (uchi no omi), and Takamuko no Kuromaro and the monk Min were named national scholars. Later in 645 the court moved to Naniwa, on Osaka Bay, the gateway to the sea routes to Korea and China.

According to the Nihon Shoki, the Reform Edict was proclaimed on New Year’s Day 646. It had four main articles. The first abolished the private ownership of land and people by royal princes, ministers and local chiefs; in return, high officials were to receive allowances in the form of the produce of a number of households. The second set up a capital region and a system of provinces and districts, with officials, checkpoints, post horses and relay stations. The third ordered household registers and tax registers to be made, and a system for allotting rice land. The fourth abolished the old levies and introduced new, uniform taxes on rice fields and households, paid in silk, cloth and other goods, along with contributions of horses, weapons, labourers and palace servants.

In the same period other edicts regulated burials — the so-called Hakusō-rei, which limited the size of tombs according to rank — sent new officials to the eastern provinces to count people and weapons, and changed the rank system. The limit on tomb size helps explain why the great keyhole-shaped mounds, symbols of clan power, were no longer built.

The ideas behind the edict came from China. Tang government rested on the equal-field system, which in principle gave land to each household and taxed each adult; on the household register; and on a hierarchy of provinces and counties run by appointed officials. Japan’s later system of handen shūju (periodic allotment of rice fields) and the taxes known as so, yō and chō were modelled on these institutions.

The move to Naniwa was more than a change of address. Naniwa was the port through which envoys, monks and goods came and went, and a new palace there — the Naniwa Nagara-Toyosaki Palace, completed in 652 — gave the reform government a stage. The map point for this page marks that palace.

Excavations in central Osaka, begun in 1954 under Yamane Tokutarō, found two superimposed palaces. The earlier one shows traces of fire and is identified with the palace that burned in 686; its construction is attributed to Emperor Kōtoku after the reform. It was very large for its time, with a spacious court and halls, including octagonal buildings, laid out on a Chinese-style plan. For many historians, the sheer scale of this palace suggests that the government of the 650s really did have ambitions to rule through a large bureaucracy.

The unity of the reformers did not last. In 653 Naka no Ōe returned to Asuka with most of the court, leaving Kōtoku at Naniwa, where he died in 654. Kōgyoku returned to the throne as Empress Saimei, and Naka no Ōe continued to hold real power.

The coup of 645 happened in the middle of an East Asian crisis. In 642 the general Yeon Gaesomun seized power in Goguryeo in a bloody coup, killing the king and many nobles; in the same year Baekje captured Silla’s western fortresses, and Silla’s Kim Chunchu went to Goguryeo in search of help and was detained. In 645, the very year of the Japanese coup, Emperor Taizong of Tang invaded Goguryeo; his army was stopped at the siege of Ansi fortress and had to withdraw. Many historians see the concentration of power in Japan as part of the same pattern: in Goguryeo, Baekje, Silla and Yamato, rulers or strongmen were centralising power to face the threat of the Tang empire.

Korean diplomacy reached Japan directly. In 647, according to the Nihon Shoki, Kim Chunchu himself came to Yamato as an envoy; the next year he went to the Tang court and secured an alliance against Baekje. That alliance destroyed Baekje in 660. Japan sent a large army to help restore Baekje, but it was crushed by the Tang and Silla at the Battle of Baekgang in 663. The defeat pushed the Yamato court to build fortresses in western Japan, welcome Baekje refugees — many of them officials and scholars — and speed up the building of a centralised state.

Further afield, 645 is also the year the Chinese pilgrim Xuanzang returned to Chang’an after sixteen years in India, where he had studied at Nalanda; the Tang capital was the centre of an empire reaching into Central Asia, and the Daming Palace, begun in 634, would soon become its seat. In the west, Arab armies had defeated the Byzantines and the Sasanian Persians in the 630s and 640s; the last Sasanian king died in 651. The Islamic caliphate was becoming a centralised empire at the same time as Japan’s reformers were trying to build theirs.

After Baekgang, Naka no Ōe moved the capital to Ōmi, by Lake Biwa, in 667 and was formally enthroned as Emperor Tenji in 668. In 669 Kamatari, on his deathbed, received the new surname Fujiwara; his descendants would dominate the court for centuries. In 670 the first nationwide household register (the Kōgo-nen-jaku) was compiled — a key step towards the census the Reform Edict had promised.

After Tenji’s death, the Jinshin War of 672 brought his brother to the throne as Emperor Tenmu, who strengthened the central government further. Codes were compiled, a large grid-plan capital was built at Fujiwara (694), and in 701 the Taihō Code established a full system of penal and administrative law. It was only then that the programme announced in 646 — provinces and districts, registers, land allotment and uniform taxes — was fully set out in law.

For this reason many historians describe the Taika Reform less as a single event than as the opening phase of half a century of state-building, driven both by internal rivalry and by the shock of war with Tang and Silla.

The text of the Reform Edict in the Nihon Shoki uses terms that match the Taihō Code of 701 very closely. This raised a suspicion: had the compilers of 720 rewritten the edict in the language of their own laws? The most famous test case was the word for “district”. The Chronicles use kōri written 郡, the term of the Taihō Code. If the reform government had really used this word in 646, documents from the late seventh century should show it.

This question, the “kōri debate” (gunpyō ronsō), divided historians in the mid-twentieth century. Sakamoto Tarō defended the essential authenticity of the edict, while Inoue Mitsusada argued that its text had been heavily revised. The answer came from archaeology: in 1967, wooden tablets from the Fujiwara palace site, including one dated to the year 699, used a different character, 評 (hyō), for district. This showed that before 701 districts were called hyō and that the Nihon Shoki’s text of the edict had been at least partly rewritten in later terms.

In the 1960s and 1970s some scholars went further and doubted that there had been any major reform in 645–646 at all, treating the “Taika Reform” as a later invention. More recent finds have moved opinion back towards a qualified acceptance. Wooden tablets from the Naniwa palace area include one dated 648, and tablets from other sites in Asuka dated 665 show administrative units already in use; together with the size of the early Naniwa palace, they suggest that real reforms were under way in the 640s and 650s. The current mainstream view — sometimes called a “new affirmative theory” — accepts that the reform government pursued centralisation, while regarding the edict’s wording as edited by later compilers.

Japanese interpretations of the reform have changed with Japan’s own politics. In the Meiji period (1868–1912), when a new government claimed to be restoring direct imperial rule, the Taika Reform was often held up as its ancient precedent, and the killing of Iruka was told as a loyal act against a usurping clan. After 1945, historians stressed instead social and economic questions — land, labour, taxation — and became more sceptical of the Chronicles’ heroic narrative, which culminated in the debates over whether the reform happened at all.

Another line of interpretation emphasises the international setting. Historians in both Japan and Korea have compared the coup of 645 with Yeon Gaesomun’s coup in Goguryeo (642), the political upheavals in Baekje in the same years and Silla’s turn to Tang, reading them as parallel responses to Tang expansion. Korean scholarship in particular stresses the role of immigrants and refugees from Baekje and Goguryeo, and of Korean state models, in building Japan’s administration — especially after 663, when many Baekje officials entered Japanese service.

From the viewpoint of Chinese history, the reforms are usually seen as part of the spread of Tang institutions — codes, examinations, registers, Buddhism, the Chinese script — across a “Sinosphere” that included Silla, Japan and later Vietnam. That view is broadly correct but can hide how selectively Japan borrowed: it did not adopt the examination system in any lasting way, kept hereditary court families at the top, and combined Chinese law with native kami ritual.

A fair summary is that the Taika Reform was both a court coup in a clan struggle and part of a region-wide transformation. The Nihon Shoki made it a founding legend; archaeology has shown that there was real substance behind the legend, but less, and later, than the Chronicles claim.

The Nihon Shoki remains the only continuous narrative. It was compiled under the patronage of Tenmu’s descendants, and Kamatari’s son Fujiwara no Fuhito was one of the most powerful men at court when it was finished. Both families had good reasons to present the coup of 645 as a righteous act and the reform as a success, so its account must be read with that in mind.

Independent checks come from outside the Chronicles. Wooden tablets (mokkan), used as labels for tax goods and as official notes, preserve the actual vocabulary of administration year by year. Palace excavations at Naniwa and Asuka show the scale of building. Chinese histories of the Tang record Japanese embassies (for example in 653 and 654) and give an outside view. Korean sources, especially the Samguk sagi, provide the peninsular side of events such as Kim Chunchu’s travels and the fall of Baekje.

Reading these together is the method modern historians use: not accepting the Chronicles wholesale, not rejecting them wholesale, but testing each claim against material that the compilers could not edit.