Changes of Dynasties Theories (王朝交替説)

Changes of dynasties theories are doctrines which say, due to the interruption in the imperial line of the Imperial Family in the Kofun period in Japan, dynasties were changed several times.


The changes of dynasties theories were born out of criticism and doubt against the concept of the unbroken imperial line which was dominant in Japan before the World War II, in which a changes of three dynasties theory, advocated by Yu MIZUNO in 1952 for the first time, was representative. However, some scholars pointed out that a prior theory of dynasty by the conquering horseback races, which was announced by Namio EGAMI in 1948 and included in the change of dynasties theories in the broad sense, affected the Mizuno's theory since both focused on the imperial line starting from Emperor Sujjn. Later Mizuno himself called his as the theory of dynasty established by the neo-hunting horseback races. It is said the theory was combined various theories freely by freewheeling thinking released from the studies of ancient history suppressed before the World War II; such as it was influenced by Sokichi TSUDA on the basis of the theory of nonexistence of ancient emperors, and the theory that Emperor Nintoku, the king of Kyushu nation, conquered provinces surrounding Kyoto and Nara to start a dynasty was none other than the development of the theory of the Yamatai-Koku Kingdom in Kyushu.

Later, Mizuno's changes of three dynasties theory has been reinforced or criticized by various researchers and at present even among the scholars denying the unbroken imperial line, not many think that there was dramatic change of sovereignty with the entirely different blood line as Mizuno advocated. What Mizuno says the transfer the base of the dynasties according to times is a common example of simply moving the political center, which does not necessarily linked with the drastic change of the political power.
In recent years the mainstream is the theory which says that the 'dynasty,' in which a specific blood line inherits great king (emperor) exclusively, established after the dynasties of Emperor Keitai and Emperor Kinmei; until then, even if great kings of several generations shared the same blood line, they were not in a form to be called 'dynasty.'

Changes of three dynasties theory' by Yu MIZUNO

In the early Showa period (before the World War II) Sokichi TSUDA was convicted for expressing that Kojiki and Nihon Shoki ("A Record of Ancient Matters" and "The Chronicles of Japan") were compiled by a highly political reason to raise the legitimacy of the Imperial family, the ruler of Japan.

However, times changed; Japan was defeated in the war and people were able to criticize Kojiki and Nihon Shoki after the war. In such circumstances, Yu MIZUNO published "Zotei Nihon Kodai Ochoshi Ron Josetsu" (Revised Introduction to the Theory on the History of Ancient Dynasties in Japan) in 1954. In this book, MIZUNO, by analyzing description of the Kojiki (including the Oriental zodiac signs of the years an emperor died and okurina [the honorary name given to an emperor after his death]), came up with a sensitively exciting hypothesis that three dynasties in different blood lines such as old, middle, and new, were changed from Emperor Sujin to Empress Suiko, which could turn over the concept of the unbroken imperial line. In the Kojiki, Mizuno focusing on that the Oriental zodiac signs of the year that emperor died were written for 15 emperors, short of half among the 33 emperors from Emperor Jinmu to Empress Suiko, pointed out the 18 rest emperors might not exist (fictional emperors). And he made a new Imperial lineage centering on the emperors of 15 generations and developed his discussion. According to the hypothesis, in matching the numbers of the emperors with those in Kojiki and Nihon Shoki, there were rise and fall of three dynasties of which the 10th Emperor Sujin, the 16th Nintoku, and the 26th Keitai were as the first emperor respectively. Three dynasties such as Sujin Dynasty, Nintoku Dynasty, and Keitai Dynasty existed and current Imperial Family is considered to be the descendant of the Keitai Dynasty.

In those days there were not many scholars who agreed with the theory of Yu MIZUNO although it drew attention among the academic community. However, the influence was not small. Later a theory, which developed Mizuno's theory critically, was brought forth in the academic community of the studies of ancient history. Starting from "Nihon Kokka no Kigen" (The Origin of Japan as a Nation) by Mitsusada INOUE (1960, Iwanami Shisho), theories were published by experts in the ancient historical science such as Kojiro NAOKI, Seiji OKADA, and Masaaki UEDA then the changes of dynasties theory came to the front in the academic community.
In his 'Kodai Kokkashi Kenkyu no Ayumi' (The Development in the Studies of the Ancient History) Yasutami SUZUKI, who organized theories concerning the ancient history, valued the changes of dynasties theory changes as 'the greatest theory after the World War II in the study of the ancient history.'
Ryoichi MAENOSO, who totally criticized on the changes of dynasties theory, also evaluated the value of negating the unbroken imperial line in his book "Kodai Ocho Kotaisetsu Hihan" (Criticism of the Theory on the Changes of Dynasties in the Ancient Times).

Three Dynasties

The three dynasties of Sujin, Nintoku, and Keitai were possibly existed as previously mentioned, and details are described follows.

Sujin Dynasty (Miwa Dynasty)

Sujin Dynasty is supposed have headquarters in Miwa region (the foot of Mt. Miwa) in Yamato and it is also called Miwa Dynasty. Yu MIZUNO called Sujin Dynasty as Old Dynasty.
Since many of the emperors and the imperial family belonging to this dynasty have the name with 'iri' such as 'Irihiko' and 'Irihime,' it is also called as 'Iri Dynasty.'
This name is limited to this period of time and it is not regarded as the Japanese-style okurina (the posthumous title given after the death of the person in question). The name of Sujin was Mimaki Irihiko Inie and that of Suinin was Ikume Irihiko Isachi. Sujin also had children such as Toyoki Irihiko and Toyoki Irihime. However, many people doubt the existence of the Emperor Sujin and the Emperor Suinin.

Assuming from the high possibility of large kofun (tumulus) being a tomb of leader (great king) of the time by the chronological order of kofun and others, the following kofun tumulus show there was a sovereignty in this region (present day Sakurai City and Tenri City): Yamato-kofun Tumulus Clusters and Yanagimoto Otsuka Tumulus built at the foot of the Mt. Miwa, in the southeast of Nara basin in the early Kofun period (from about the middle of the third century to the early fourth century), and large scattered kofun with the hill length of 300 meters to 200 meters such as Shibutani Mukoyama-kofun Tumulus (identified as a mausoleum of Emperor Keiko), Hashihaka-kofun Tumulus (surmised by some researchers to be a grave of Himiko), Andonyama-kofun Tumulus (identified as a mausoleum of Emperor Sujin), Mesuriyama-kofun Tumulus, and Nishitonotsuka-kofun Tumulus (identified as the grave of Tashiraka no Himemiko). Furthermore according to the "Kojiki" and the "Nihon Shoki," the capitals of these kings overlap with a region with previously-mentioned kofun, the regime started with Emperor Sujin is estimated to have been established centering on this region and can be called as the Miwa Regime.

From the viewpoint of the formation of the ancient state of Japan, the Miwa Regime can be thought to be the first Yamato Administration. The date this regime formed is thought to be about the middle of the third century or the end of the fourth century. That was the early Kofun period when formalized giant kofun were built. The nature of the regime is considered not like that of the magical regime of Yamatai-koku Kingdom with Queen Himiko who 'used the art of shaman and often misled the people,' but more powerful government remaining the religious nature.

Ojin Dynasty (Kawachi Dynasty)

Ojin Dynasty was also called as Kawachi Dynasty since many imperial palaces and the mausoleums of the emperors were built in Kawachi area. It was also called 'Wake Dynasty' since many emperors and imperial family belonging with this dynasty had 'wake' in their names. Kawachi Dynasty occupies a big position in the previous theory on the changes of the dynasties. The reason lies in that Kawachi Dynasty existed in the position to connect two dynasties of the former and latter. Yu MIZUNO called this dynasty the Middle Dynasty which was generally called the first Yamato Administration, the second Yamato Administration and so on.

In addition, there is a view which makes the Emperor Ojin be a fictional Emperor. In this view advocating that from the legendary birth of Emperor Ojin, Emperor Ojin who was originally the same person as Emperor Nintoku was created dividing from Emperor Nintoku to connect Miwa Dynasty and Kawachi Dynasty, this dynasty is called Nintoku Dynasty. Yu MIZUNO also defined this dynasty as Nintoku Dynasty.

The collateral evidence of the article in Sosho (the history books of Liu Song Dynasty of the Southern Dynasties of China compiled in 488) that the five kings of Wa (ancient Japan) sent envoys 10 times to Chinashows the five kings of Wa could be little doubt of being great kings of Kawachi Dynasty (Ojin Dynasty), while various theories are concerning the identification of each king, it is very likely that the whole dynasty existed.

In addition, following facts show that a base of the powerful political power was placed in Osaka Plain during Kawachi Dynasty; the current existence of huge keyhole-shaped mounds such as Konda Gobyoyama-kofun Tumulus (the mausoleum of Emperor Ojin) in Furuichi-kofun Tumulus Clusters in Kawachi and Daisenryo-kofun Tumulus (the mausoleum of Emperor Nintoku) in Mozu-kofun Tumulus Clusters in Izumi, and the capitals each established in Kawachi or Izumi in Osaka Plain, such as the Osumi no Miya (Palace) of the 15th Ojin in Naniwa, the Takatsu no Miya of the 16th Nintoku in Naniwa, and the 18th Hanzei in Shibagaki in Tajihi (Matsubara City, Osaka Prefecture). It is certain that based in Kawachi, it built a port in Kawachi-wan bay, maintained the Suigun Navy, and controlled of the Seto Inland Sea. This government was a maritime state connecting to Asia having superior seamanship such as sending envoys to Sung Dynasty and sail to Korean Peninsula.

Teiji KADOWAKI was one of the disputants who criticize this Kawachi Dynasty Theory. According to Kadowaki, the development of the Kawachi Plain was not the establishment of a new dynasty but the advance by the first Yamato Administration to the Kawachi region. In the Kawachi Dynasty Theory, there are different opinions as follows: One by Kojiro NAOKI and Seiji OKADA that a Kawachi power which controlled the Seto Inland Sea to enlarge its power conflicted and overthrew the first Yamato Administration, another by Masaaki UEDA that after the fall of the Miwa Dynasty (Sujin Dynasty) it was succeeded by Kawachi Dynasty (Ojin Dynasty), and the other by Mizuno and Inoue that a Kyushu power invaded to the area surrounding Kyoto and Nara as conquerors during the reign of Emperor Ojin or Emperor Nintoku.

Keitai Dynasty (Omi Dynasty)

The Emperor Keitai is considered to be the fifth descendant of Emperor Ojin, but the decision is divided whether this is a fact or not. Yu MIZUNO thought that Emperor Keitai who was from a local ruling family in either Omi or Echizen usurped the throne.

Since the Emperor Keitai entered Yamato not immediately after the enthronement but the 20th year later after moving from place to place such as Kitakawachi or Minami-yamashiro, there are two following theories: One that considers due to a power in Yamato which didn't allow the enthronement of Emperor Keitai, the region was in the combat situation (theory by Kojiro NAOKI) and the other that, since Keitai, the emperor of the maternal side, was a successor to the throne in the linage of the Okinaga clan in Omi, which daughters often married those in the great king family, there was no such change of dynasties as usurpation of imperial throne (theory by Kunio HIRANO).

Many scholars took that even if Emperor Keitai was in fact the fifth descendant from Emperor Ojin, in view of the notion of dynasty in European sense, it was really a separate dynasty and independent of the theory on the changes of dynasties there was change in the imperial line from Emperor Keitai. However, some scholars think that it is questionable to think that Keitai dynasty as a separate 'dynasty' because at the enthronement of Emperor Keitai he inherited the form of government as it was from the previous government, and in the blood line, he inherited the imperial throne as a man whose wife was a princess of the previous great kings family and became irimuko (man who takes his wife's premarital family name).

Katsuragi Dynasty Theory

It was the theory advocated by Kensaburo TORIGOE that Emperor Jinmu and so called Kesshi-Hachidai (Eight undocumented Sovereigns), who were denied the existence in the changes of the three dynasties theory, were actual persons and they set the base on Katsuragi region in Nara Prefecture before the reign of Emperor Sujin who destroyed the dynasty. For details, refer to the article of 'The Katsuragi Dynasty Theory' from the argument in the Theory of the Existence of the Kesshi-Hachidai.

It is thought that strong Kawachi Dynasty were built by holding the maritime power of the Seto Inland Sea and having the cooperation of the Katsuragi clan, an influential local ruling family in the southeast part of Nara basin. Emperor Nintoku married Iwa no Hime, the daughter of KATSURAGI no Sotsuhiko, as his wife to have three later emperors such as Richu, Hanzei, and Ingyo. Emperor Richu married Kurohime, the grandchild of Sotsuhiko, as his wife to have ICHIBE no Oshiwa no Miko who married Haehime, the great-grandchild of Sotsuhiko, as his wife to have the later two emperors, Kenzo and Ninken. Furthermore, there is a legend in which Emperor Nintoku married Karahime, the daughter of KATSURAGI no Tsubura no Omi as his wife to have later Emperor Seinei. It can be said that there was a close relationship between the Katsuragi clan and Kawachi Dynasty, independent of these descriptions in the "Kojiki" and the "Nihon Shoki" are historical facts.

Dynasty by the Conquering Horseback Races Theory

This is the theory advocated by Namio EGAMI that in the end of the fourth century, hunting horseback races came from the Continent to Osaka Plain through Northern Kyushu and conquered the dynasty existed to establish a new dynasty.

Kyusyu Dynasty Theory

Developing the Yamatai-koku Kingdom in Kyushu, by the Kyushu Dynasty Theory advocated by Takehiko FURUTA that the Kyushu Dynasty was established with the capital Dazaifu but was destroyed by the Yamato Administration triggered by the lost in 'Battle of Hakusukinoe' (Battle of Baekgang) in 663, most of the immemorial myth, the genealogy and the achievements of the Imperial Family in Kojiki and Nihon Shoki before later Emperor Tenchi and Emperor Tenmu seized the political power through the incident called Taika Reforms were fiction by plagiarism from the Kyushu Dynasty and until then, the Yamato Administration was not a unified dynasty. The two dynasties existed at the same time is called 'Pluralistic Views of Ancient Japanese History' by Furuta.