The Emperor (Tenno) (天皇)

It is the royal crest of the Emperor and the Emperor's family. It originated from the Imperial chrysanthemum crest on the Goshi-yaki (the swords quenched by Emperor Gotoba) of the Japanese sword owned by Emperor Gotoba.

Emperor (Tenno) is a position, or an individual who is at the position, seen as the symbol of Japan that integrates the Japanese people under the Constitution of Japan. Also, it is a title (title of monarch) or a posthumous title respecting the Emperor and monarch.

They are the monarchs of Japan inherited from ancient times. In this section, the matters concerning the position and the individual successive Emperors following the first Emperor, Emperor Jinmu, will also be described.

The origin of 'Tenno'

There are several theories for the origin of the title of 'Tenno.'

There is a theory stating that it was adopted from 'Teno daitei' or 'Fuso Taitei Tokofu,' which means the Polestar in ancient China and was also adopted into Taoism.

There is a theory stating that the Gao Zong of Tang (reigned 649-683) once called himself 'Tenno,' not Emperor, originated from Taoism like mentioned above, and was introduced into Japan.

There is a theory stating that around 5th century, they were called 'Kai Daio,' 'Kikoku Daio,' or simply 'Daio' (great king) externally, but it was fixed to 'Tenno' in the Reign of Empress Suiko or the Reign of Emperor Tenmu.

The theory stating that it was first adopted in the Reign of Empress Suiko (theory by Sokichi TSUDA before the war) is also persistent. However, the theory stating that it was adopted in the period of Emperor Tenmu in latter half of 7th century, which was right after the usage of the title by Emperor Gao Zong of Tang mentioned above, has the power, after the mokkan (wood strip), which has the Emperor's handwriting written on, was founded in the Asukaike Ruins in 1998.

The history of the title

In recent year studies, the theory stating that the title 'Tenno' was adopted sometime after the period of Emperor Tenmu (latter half of 7th century) is a powerful one.
Traditionally, it was pronounced 'Ten-o.'
It is said to be changed to 'Tenno' in the Meiji period by renjo (change of pronunciation in Japanese when two particular sounds adjoin). It is written 'Tenwau' in historical kana-zukai (rule of writing Japanese syllabary).

The history of the change of title of the Emperor is described below.

Ancient times

Before the title Tenno was born, they called the position of Emperor 'Yamato Okimi' or 'Teno' domestically, and called 'Wao,' 'Wakokuo,' 'Daiwao,' and so on externally, in Wakoku (name of the country before it was called Japan). Before that, they were called Suberagi, Sumeragi, Sumerogi, Sumeramikoto, Sumemimanomikoto, and so on.

Title under the political system based on the ritsuryo codes (the legal codes of the Nara and Heian periods)

A regulation in the ritsuryo codes ('Gisei-ryo,' or the regulation of ceremonies code) regarding the title to be used for the Tenno states that the Emperor should be called 'Sumemimanomikoto,' 'Sumeramikoto,' or another such title in accordance with the customs of that time; this was despite the fact that there were already seven ways of addressing the Emperor—'Tenshi' at ceremonies, 'Tenno' in Shosho (imperial edicts or decrees), 'Kotei' in relations with China (domestic and diplomatic), 'Heika' when addressed by vassals in close proximity, 'Daijo-Tenno' when retired, 'Joyo' when going out, and 'Shaga' when traveling—because these names are only used in writing ('Tenshi' attending ceremonies in particular were addressed as 'Sumemimanomikoto'). The death of Tenno is called Hogyo, the present Emperor is called Kinjo-Tenno, and the departed Emperor is called Taiko-Tenno until his posthumous name is decided.
His spouse is called 'Kogo.'
He calls himself 'Chin.'
Vassals also called him 'Shison.'

Further, according to "Shoku-Nihongi" (the chronicles of Japan II), in Nara period (762-764), kanpu-shigo (Chinese style posthumous name) was chosen for the Emperors of forty-one generations, from Emperor Jinmu to Empress Jito, and for Empress Genmei and Empress Gensho at once by OMI no Mifune, but those are shigo (names for the individuals) and the title 'Tenno' doesn't directly concerns with them.

Medieval period

After the Heian period until the Edo period, they were called in various ways such as Mikado, Kinri, Dairi, Kinchu, and so on. Mikado' originally means the gate of the Imperial Palace, and Kinri, Kinchu, and Dairi mean the Imperial Palace itself. These are euphemistic expressions hesitating to call the Emperor directly. It is also same for Heika (meaning the informing usher at the bottom of the stairs). Also, expression Okami, or Shujo (meaning person above), was used. Tencho is a word meaning Tenno Dynasty, but its meaning shifted and came to be used for the Imperial Court, Japan itself, or rarely Tenno himself. They were also called Sumeramikoto, Sumerogi, Suberaki, and so on, and these words remained as gago (sophisticated words).
Also, 'Kogo' had come to be also called 'Chugu.'
Kinjo-Tenno was also called Togin no Mikado, and retired Daijo-Tenno was shortly called Joko, and was also called 'Sento' or 'In.'
When he became a priest, he was also called Hoo (Cloistered Emperor). After Emperor Kokaku abdicated the throne to Emperor Ninko, the position in fact didn't exist in the political system in and after Meiji period. This is because the present and former Imperial House Act didn't provide the rule for the abdication, and stated that the Koshi (Crown Prince) would be enthroned after the Hogyo of Tenno.

In and after the Meiji period

The title of Emperor was unified into 'Tenno' for the first time by the Constitution of the Empire of Japan (Meiji Constitution). However, in diplomatic documents and so on, 'Nihonkoku Kotei' (Emperor of Japan) was used afterwards, too, and several similar expressions can be found in official domestic documents, also (look at 'Nihonkoku Kotei' for the usage of the expression). As a result, it can be thought that the title was not unified completely as 'Tenno' (Tenno still was sometimes called Tenshi-sama by common people). He was also called 'Dai Gensui Heika' (great majestic marshal), for he had the supreme command of the Japanese Army and Navy. Conversationally, euphemistic expressions such as Okami or Shujo, Okami or Seijo, Togin, Kashikokiatari, and Kamigoichinin and so on, were also used.

Present time

Further, generally in the press and other media, the honorific title used for the Emperor is 'Heika,' regulated in the Imperial House Act, and called 'Tenno Heika' (his Imperial Majesty). To avoid the confusion with the other Emperors, the name 'Kinjo Heika,' other than 'Tenno Heika,' is also used in the official documents of the Imperial Household Agency and so on. When called as the second person in conversation, most of the time is simply called Heika if it is clear whether the individual is the Emperor or the Empress from the context of conversation. Tenno is sometimes called 'Tenno in nowadays,' 'present Tenno,' and 'Kinjo Tenno' as the third person, which are without honorific titles, but it is rare to call Tenno in euphemistic expressions such as 'Okami' and 'Seijo' in recent years.

In some publications, examples using title 'OO (name of Japanese era) Tenno,' without using honorific titles to Kinjo Tenno for the third person (for example: Akihito), can be seen here and there. However, 'OO (name of Japanese era) Tenno' should be a posthumous name sent after Tenno's Hogyo, so essentially a usage like this is a mistake.

Naming in English

A word meaning Tenno in English is basically Emperor with capital E. In some cases, the definite article (the) is used, but the principle of using capital E can't be broken (for it is treated as a proper noun). An honorific title used when referring to the Emperor is His Majesty, sometimes is written as His Imperial Majesty, and sometimes is also abbreviated as H.M. Since Tenno is a male, her Majesty basically means 'Kogo,' but the abbreviation is also H.M., same as the Tenno. When mentioning '~Tenno Heika' officially, the name is mentioned after His Imperial Majesty (the) Emperor. When mentioning both Tenno Heika and Kogo Heika, it is expressed as Their Imperial Majesties Emperor and Empress. Generally, Your Imperial Majesty is used when speaking to Tenno, and the form of speaking to 'the dignity as the Emperor' is taken. Further, Denka, an honorific title for the Imperial families excluding Tenno and Kogo, is His/Her Imperial Highness, but Imperial can't be omitted in this case.

In fields of history and others, there are some cases of mentioning Tenno or Mikado, to express Tenno as the being peculiar to Japan.

Korean Peninsula and the naming of Tenno

The Korean Peninsula existed dependent upon successive Chinese Dynasties for a long time, and 'Tenshi' and 'Kotei' was a title for only one person that ruled the world in the Zhongyuan Dynasty, to which Korean Peninsula had belonged. Because of that, in Korea, titles of Ko and Tei (both meaning the Emperor) for the Tenno's family were not accepted, and the titles such as 'Wao' and 'Nihon Kokuo' (both meaning the King of Japan) were used. In modern times, demanded by the Empire of Japan winning the Japanese-Sino War, the Chinese Suzerainty over Korea collapsed after Korea left from the Sakuho system (the Chinese vassal system), and called the Tenno of Japan the Emperor for the first time after being newly subordinated to the Empire of Japan. After that, the title of Tenno was used in Korea during the period of Japanese rule. After the independence of Korean Peninsula, the translation 'Emperor' meaning Emperor in English was not inherited, but the title 'Nihon Kokuo' (Nichio) was used, and following that, 'Koshitsu' (Imperial family) was called 'Oshitsu' (King's family), and 'Kotaishi' (Crown Prince) was called 'Oseishi' (heir of King). After that, the title 'Tenno' had come to be used commonly, and concerning 'Koshitsu/Oshitsu' and 'Kotaishi/Oseishi,' they were used equivalently. There is a theory stating that the reason for this naming is not only because of 'little Sino-centrism,' but also because of retaliation for being demoted from 'Kotei' to 'O' (King) once again by Japan even after they came to call themselves the Korean Empire and held the title of Emperor without hesitation after the independence from the Sakuho system of Qing. Recently, the President Dae-jing KIM worked on the mass media to follow the custom of various countries and use the title 'Tenno,' but the mass media split into those that follow and those that do not. And the next President Moo-Hyun ROH showed an attitude to convert the former policy because they were not prepared to decide to use either 'Tenno' or 'Nichio' for they did not confirm whether the title Tenno was used worldwide. However, the title Tenno is used in official diplomatic ceremonies.

The title of the Tenno's spouse

Before the Meiji Restoration, Tenno had more than one spouse other than Kogo, because a concubine was generally accepted. The title that the Tenno's spouse could hold was decided by the social standing of the family she was from.

Since monogamy spread through the people of the country from the influence of civil law after the Meiji Restoration, it also spread through Imperial family and nobility. However, since Emperor Meiji had a concubine, the first Tenno to put monogamy into practice was Emperor Taisho. The following Tenno and Imperial families had only one spouse, based on monogamy.

Before the Meiji Restoration
Koi (Jokan)
Bunin or Fujin (the title of spouse before the titles above were made)
After Emperor Taisho

Family name of Tenno

Tenno and his family are supposed to have no shisei and myoji (both meaning family name). In ancient Japan, shisei, or ujina and kabane, was positioned as a name granted by Tenno to his retainers (Shisei system). Tenno stood in a transcendent position so that no one existed above to grant Tenno a shisei, and that is why Tenno didn't have shisei. This is a very peculiar situation, with no similarities seen in Eastern Asia.

However, Daio-ke (antecedent of Tenno's family) is said to have had family name, before uji-kabane was systematized.
The fact that the five kings of Wa (ancient name of Japan) in the 5th century called themselves 'Wasan,' 'Wasai,' and so on, can be seen in "Sosho" Wakokuden (articles about Wa written in Sung) and Bunteiki, and it is clear that the kings at that time had the family name of 'Wa.'
From this fact, it is believed that the king of the Yamato Dynasty needed to have a family name in order to form a Sakuho relationship with Sung (Southern Dynasty). Further, there is an opinion that Daio-ke had family name until the beginning of 7th century since there is a description in "Zuisho (Sui Shu)" Wakokuden (articles about Wa written in Sui) stating that the family name of Wakoku-o (king of Wa) is 'Ama' or 'Ame,' but because it is not a single letter family name seen in Chinese style, an opinion that 'Ama' or 'Ame' is not a family name is supported. A theory stating that the family name 'Wa' of Daio-ke was abandoned at the end of the 5th century when leaving the Sakuho system in China, or was abandoned in between the end of the 5th century and the first half of the 6th century when the Shise system was established, is powerful.

Takashi YOSHIDA states that the reason Daio and Tenno stood aloof from 'sei' (family name) system by not having it was because Wakoku (country of Wa) left the Chinese Sakuho system at the end of the 5th century, and was not taken into the system as Wakoku-o even during the Reign of Empress Suiko at the beginning of the 7th century.

Succession to the Imperial Throne of the Emperor

Refer to sokui no rei (ceremony of enthronement) for the successive Emperors in and after Meiji period.

Succession to the Imperial Throne is when an heir to the Imperial Throne, such as the crown prince, succeeds to the Imperial Throne (position of Emperor). It is almost a synonym for the succession to the King's Throne or succession to the Emperor's Throne, meaning the succession to the position of King and Emperor, in other countries. The succession to the Imperial Throne of the Emperor was provided for in the Constitution of the Empire of Japan and in the Constitution of Japan.
In the Constitution of Japan, it states that the 'Imperial Throne, which is hereditary, is succeeded under the rule of the Imperial House Act decided by the Diet'
(Article 2 of the Constitution of Japan).
And in that Imperial House Act, it states that the 'Imperial Throne is succeeded to a male in the male line of the Imperial lineage'
(s Imperial House Act a1).

Regulations in the Constitution

Regulations for the Emperor in the Constitution of Japan and the Constitution of the Empire of Japan are described here.

Emperor under the Constitution of Japan

At present, the Emperor is stated in chapter 1 of the Constitution of Japan. It is positioned as 'The symbol of the country of Japan and the symbol of unity of the people in Japan' in the Constitution of Japan. Since there are no regulations about the head of state in the Constitution of Japan, arguments about the position of the Emperor have taken place, but officially, he is treated as the head of state inside and outside Japan. No functions in the government are given, except for ones provided by the Constitution.

Emperor under the Constitution of the Empire of Japan

In the Constitution of the Empire of Japan, the position is provided in Article 1 of the Constitution of the Empire of Japan that 'The Empire of Japan is ruled by the Emperor in unbroken line,' and article 4 of the Constitution of the Empire of Japan states that 'The Emperor is the head of state of the country, and controls the right to rule depended on the articles of this Constitution,' which clearly provides as 'the head of state,' unlike the Constitution of Japan.

When the Constitution of the Empire of Japan is interpreted without argument, it can be read as if the Emperor had very strong powers. However, also in and after the Meiji period, the Emperor rarely ordered directly and practiced politics.
On this point, there is an opinion insisting that in fact, the Emperor was similar to those in present day Japan and Great Britain, which holds the principle that 'he reigns, but doesn't govern.'
However, there are other opinions insisting that it is different, because the Emperor used his influential power in important political situations.

Shinto religion, Buddhism, and the Emperor

The history of the Emperor can go back to the mythological age. In present day, the Emperor and Shinto religion are still connected in ceremonies such as Niname-no-matsuri (ceremonial offering by the Emperor of newly-harvested rice to the deities). The Emperor is significant not only for his constitutional functions, but also for the existence as the one that holds 'inori' (prayer) in Shihohai, which is a court ritual held to pray for the welfare of the country, etc. Refer to 'state sponsorship of Shintoism' and 'fundamental character of the nation' for the relationship between the Emperor and Shinto religion from Meiji period to the period right after the war. Further, the Emperor was deeply connected with Buddhism until the Edo period, and until 1871, there were mortuary tablets of the successive Emperors in Kokudo-no-ma (room with a black door) in the Imperial court. Memorial services were held according to Buddhist rites. After the Meiji Restoration, each and every function held according to Buddhist rites that continued for a thousand years have stopped, the mortuary tablets of the Emperors and the Imperial families, which were called 'Sonpai,' were gathered in Sennyu-ji Temple in Kyoto, and the Emperor became estranged to Buddhism since the relationship between both was assumed to have been ended.

History of the Emperor

The Emperor held important authority in Japanese history, but the length of the period which the Emperor held the actual sovereignty as the ruler is extremely short compared to the length of the period the Emperor had existed, and most of the sovereignty was held by nobilities other than the Emperor, samurai families, bureaucracy, etc. Particularly after the Kamakura Bakufu (Japanese feudal government headed by a shogun) was established, the head family of the samurai families inheritably succeeded the position of Seii Taishogun (literally, "great general who subdues the barbarians"), and at least in basic domestic affairs and diplomatic affairs, they reigned as the highest authority. However, the position of the Emperor was never abolished by those authorities, and at least formally, the authorities at those times respected the authority of the Emperor, and most of the time, they held their position with that background. For example, the assumption of Seii Taishogun, who was the sovereign of samurai government which had supremacy throughout the country, was claimed to be granted by the Emperor in a form of Imperial proclamation, and most of the time, the man at power used the Emperor's authority to make a political opponent as choteki (enemy of the Emperor) to justify his right to rule. However, whether the samurai governments like the bakufu recognized their right to be used fully in domestic affairs and in diplomatic affairs must be considered, because those men in power consulted the Imperial Court in diplomatic emergencies (the Mongolian Invasions, the Western ship coming to Japan at the end of the Edo period, etc). It is said that sometimes, especially big authority planned to abolish or usurp the position of the Emperor, but it is said that no one has succeeded.

Kamiyo (the age of the gods) and the origination of the Emperor

The genealogy of the Emperor's family is made based on history books including the 'Kojiki' (A Record of Ancient Matters) and 'Ninhonshoki' (Chronicles of Japan), and the origin is regarded as Emperor Jinmu, who was enthroned in 660 B.C., and furthermore gods such as Kuninotokotachi who are the progenitor of the Emperors. However, the Nihonshoki was compiled by the Imperial command of Emperor Tenmu, and includes many myths and legends that are hard to prove historically. Because of that, the actual existence of folklores and achievements relating to the ancestors of the Imperial Family and the existence of the Emperors in the early days are usually seen with doubt. Especially with the Emperors of Kesshi-Hachidai (Eight Undocumented Sovereigns), a negative theory stating that the history of the Imperial Family was padded out following the revolutionary idea (Shinisetsu, or theory of predicting future with magic) in Ancient China is the main stream in learned society after the war (there are also theories that support the existence).

The origin of the Imperial Family that can be proved historically is back around Kofun (tumulus) period when Yamato Daio (Daio) ruled in the Yamato sovereignty. Many theories, such as a theory stating that the appearance of large keyhole-shaped tomb mounds seen in and after middle 3rd century suggests the establishment of unified government in the Japanese Islands, and the dynasty established at that time were the ancestors of the Imperial Family, a theory regarding the lineage of Himiko of the Yamatai Kingdom, if it existed in the Kinki region of the Yayoi period, as the ancestors of the Imperial Family, and a theory stating that the dynasty of the ancestors of the Imperial Family was established in 4th century, has been presented, and has not been settled.

The five kings of Wa

The oldest description in history books in China is about the kings of 'Wa' who tribute to Sung Dynasty (Southern Dynasty) in the period of North and South Dynasties (China). There is description about the five kings of Wa (San, Chin, Sai, Ko, and Bu) remaining in the Chinese history book in the 5th century, "Sosho (Sung Shu)" Ibanden, Wakokujo (Wakokuden, or description about Wakoku). These five kings are judged as the Emperors from Emperor Nintoku and Emperor Richu through Emperor Yuryaku (there are several theories about the judgment), and the theory which regards these five kings to be the ancestor of the Imperial Family is influential.

These five kings, in return of the tribute, were taken into Sakuho system as 'Wakoku-o' by Chinese Dynasty, and it is estimated that this title was used diplomatically. As for the title of the king inside the country, there are inscriptions '治天下獲加多支鹵大王' and '獲加多支鹵大王' carved in iron swords excavated from tumulus in Kumamoto Prefecture and Saitama Prefecture (common opinion regards 獲加多支鹵大王 as Wakatakeru, which is the Japanese style posthumous name for Emperor Yuryaku), and it can be seen that the title '治天下大王' or 'Yamato Daio' was used.

In "Sosho," johyobun (memorial to the Chinese Emperor) like below by Bu, King of Wa, is quoted.

Our country, which was taken into Sakuho by the Emperor, is far away from China, and has become a hanpei (protector of the Emperor) as indirect subject. Our ancestors, from the past, wore armor, roamed through mountains and rivers, and without a days rest, conquered fifty-five regions of the Emishi (one of natives in Japan) in the East, conquered sixty-six regions of Shui (one of natives in Japan) in the West, went overseas and conquered ninety-five regions in the North crossing the sea, and established a powerful country. The rule of right is spread without interference, the territories are spread wide, and the dignity of China has spread to far distances.

Our country has served China for generations, and has never mistaken the year of tribute. I am an incompetent man, but graciously succeeding the will of the last king, lead the commanded people of the country, and prepared ships to tribute by going through Baekje to be united with China, the center of the world.

However, Goguryeo unreasonably tried to conquer Baekje, snatches the bordering regions, and didn't stop the slaughter. Because of that, the tribute stopped because the ships can't advance smoothly, and even though the envoy is on the way, he has not necessarily completed his objective.

My deceased father Saio became furious about the obstruction of the road from Wa to China by the enemy Goguryeo, a million soldiers were moved by this justice, and were about to go overseas in a massive force. However, just then, I lost my father and brother, and have wasted my valuable opportunity. And because of mourning my father and brother, I can not move the military, and after all, I have rested for a while and have not unnerved Goguryeo's force. By now, I have decided to accomplish my father and brother's will by preparing weapons. To be a brave man with justice, I will not shrink back even if I see a naked sword swung in front of my eyes.

If we can unnerve Goguryeo's powerful force and overcome this difficulty with the Emperor's blessing, you will not change the reward for the meritorious deeds of my ancestors. I will keep my allegiance and appoint myself as Kaifu Yitong Sansi (Supreme Minister) and grant titles to each of my own commanders.

As for the origin and lineage of Emperors around this period, there is also a theory stating that it was not 'bansei ikkei' (an unbroken line) like described in the Kojiki (Records of Ancient Matters) and the Nihonshoki (Chronicles of Japan), but had complex movement of powers in behind and between the powerful local ruling families in various places inside Wakoku. For example, when Emperor Seinei, son of Emperor Yuryaku, didn't have a successor, it is assumed that Emperor Ninken and Emperor Kenzo, grandsons of Emperor Richu, succeeded the Imperial throne, but there is also a theory stating that in fact, it was an usurpation of the Imperial throne.

Also, Emperor Buretsu, son of Emperor Ninken, did not have a heir, and Emperor Ketai, who is said to be a descendant of five generations counting from Emperor Ojin, succeeded the throne, but since the blood line from Emperor Nintoku had been broken off by this, there is also a theory that a change of Dynasty took place.

However, as for the actual circumstances that occurred back then, the historical records are limited to those with a 'bansei ikkei' history view in later generations, like in the "Nihonshoki" and so on, so there are also objections to the theories mentioned above. Back then, an idea stating that not only one blood line succeeded the throne of Wakoku, but the throne was succeeded in between plural powerful ruling families (theory of joint sovereignty) can also be seen.


It is said that around the period of Emperor Kinmei (middle of the 6th century), the son of Emperor Ketai, the lineage of the Emperor, which had been unstable, was stabilized. After Emperor Kinmei, the systems and cultures of China had begun to be assimilated actively, and in the beginning of 7th century, like the assimilation of kani system (system indicating court ranks by headgear colors), the government with the Imperial Family in the center had begun to be formed.

Also, in this period, it can be seen in "Zuisho" that the Emperor proclaimed himself as 'Tenshi' (Emperor) against the Yang-di of Sui. From this fact, there are some opinions establishing the title of Emperor at the beginning of the 7th century.

From the Reformation of Taika to Insei (cloistered government)

After the Reformation of Taika, the movement to construct the government and system of the country with the Emperor in the center was activated by introducing Ritsuryo, which is the system of rules and regulations in China (Tang). Such trials did not progress at once because of resistance from the local ruling families, but finally, they were completed by Emperor Tenmu and his successors. Especially Emperor Tenmu, who usurped the Imperial throne with the military, exercised absolute powers. It is during the reign of Emperor Tenmu that the Emperor had begun to be considered as Arahitogami (kami, or god who appears in this world in human form). The theory that Emperor Tenmu was the first to use the title of Emperor is persuasive. Further, it is believed that the title of the King, before the establishment of the title of the Emperor, was Wakoku-o and Wao (diplomatically), and Amenoshitashiroshimesuokimi (domestically).

Under the Ritsuryo system, the Emperor stood on the organization of Daijokan (Grand Council of State) and exercised his actual powers, but since the form of the government conformed to rules and regulations, it was relatively stable. Approvals of the Emperor were needed to enforce principle political matters, and the importance of the Emperor was secured. However, around the beginning of the Heian period during the middle and latter period of the 9th century, the Northern House of the Fujiwara clan began to assume as Sessho (regency) and Kanpaku (chief adviser to the Emperor), which acted in place of the Emperor. Especially Emperor Seiwa, who was enthroned in 858, was only nine years old, and there was no precedent of such young Emperor until then. The enthronement of such a young Emperor shows that the Emperor gradually lost his actual power, and this form of government is called Sekkanseiji. The background of the establishment of Sekkanseiji was that because threats inside and outside the country had gone, politics had been stabilized, and the center of the politics began to be moved to the management of ceremonies and personal matters. Because of that, it is thought that it was possible for the Northern House of the Fujiwara clan (Sekkanke, or line of regents and advisers) to act as supreme power in place of the Imperial Family. Also, it is considered that the source of Sekkanke power was the continuation of the secure position of the maternal grandfather of the Imperial family by Sekkanke. However, this series of phenomena, oppositely reflecting the fact that the position of the Emperor was stabilized, and the possibility of the threat being abolished had been reduced. Around this time, in the Kanto region, TAIRA no Masakado, who was an Imperial descendant of Emperor Kanmu for five generations, suppressed the internal conflicts between his relatives, and when he intervened in disputes amongst the neighboring provinces, he opposed the local Kokushi (provincial governor), soon caused insurrection and called himself 'Shinno' (new Emperor), banished Kokushi appointed by the Imperial Court, and appointed his Kokushi to 7 provinces in Kanto and Izu region. It can be said that a new country was established, but Masakado, like calling the Emperor in Kyoto (at that time was Emperor Suzaku) 'Honno,' didn't completely deny the authority of the Emperor. Also, the insurrection of Masakado itself couldn't gain support of the samurai in Kanto, and the new government collapsed because Masakado died in battle in just 3 months.

Emperor Gosanjo, who was enthroned in the latter Heian period, could act relatively freely because he was in position without any Sekkanke amongst maternal relatives. Because of that, like the establishment of Kiroku Shoenken Keijo (Kirokujo, or Land Record Office), he developed various original new policies. There is a theory that Emperor Gosanjo, even after he abdicated the throne, planned to manage politics as Joko (retired Empire). If the theory is correct, it can be regarded as the first Insei preceding the Shirakawa Insei (ruled by the retired Emperor Shirakawa), but since Gosanjo had passed away in less than a half year after abdication, his real intention remains a mystery. Emperor Shirakawa, who was the son of Gosanjo, needed to become a conservator for his son, Emperor Horikawa, and his grandson, Emperor Toba, since they both were enthroned in their childhood, gradually came into power, and finally, he came to reign over the Imperial Court as an absolute monarch. By this development of Insei, the power of Sekkanke was weakened remarkably. Joko (In), after establishing Insei, privately formed relationships between lord and vassals with many nobilities and reigned as "Chiten no Kimi" (actual ruler of the country), and since it was based on the parental authority as father and the position as the lord of nobilities, his position was more firm than that of Sekkanseiji, which was a conservator as maternal grandfather of the Emperor. Chiten no Kimi, holding Hokumen no Bushi (the Imperial Palace Guards) as his own military power, formed the relationships between lord and vassals with samurai such as the Taira and Minamoto clans and placed them in important positions, but as a result, it opened the way to solving political disputes by military power, and led to the birth of the Taira clan government and the establishment of the Kamakura Bakufu (Japanese feudal government headed by a shogun) by the Minamoto clan. Retired Emperor Gotoba further established Saimen no Bushi (Imperial Guards), but was abolished after the defeat in the Jokyu War. After the Jokyu War, the Imperial Court lost its military power and was subordinated to the bakufu, and this sometimes resulted in a situation where the Emperor was appointed upon orders from the bakufu. After this, Insei continued until the Edo period, but the period in which it formed actual political power is regarded as about 250 years from the Shirakawa Insei until the period of Emperor Goenyu in the Northern and Southern Court Period (Japan). After the death of Retired Emperor Goenyu, almost all of the few political powers left in the Imperial Court were requisitioned to bakufu by Yoshimitsu ASHIKAGA, many nobilities also subordinated to Bakufu by forming lord and vassal relationships with Muromachi-dono (the head position of Muromachi Bakufu inherited by Ashikaga family), Insei lost the objective to rule, the Imperial Court lost its functions as a government, and the position fell into a profitable community by nobilities (Kuge) with the Emperor in center.

The Medieval period

As for the system of the country during the Medieval period, it is generally characterized as the regression of the Emperor and Kuge and extension of Buke (samurai families), but the theories are various, like the kenmon taisei theory, a theory that suggests Kuge and Buke both kept the country together, is presented. Since Koryo (Imperial demesne, or Kokugaryo) under the Ritsuryo system persistently continued even after the spread of the manorial system, there was room for Joko to use considerable power until the establishment of the Kamakura Bakufu. However, the loss of the Emperor's authority after the Jokyu War (1221) was remarkable, and like diplomatic efforts against Genko (Mongol invasion attempts against Japan) and foreign trade, sending ships to Tang, they were both lead by the Kamakura Bakufu, and showed the unity of power amongst Buke. In many times, the families of Kuge were split because of the advance of Buke. Also in the Imperial family, it was split into Daikakuji-to (Imperial lineage starting with Emperor Kameyama) and Jimyoin-to (Imperial lineage from Emperor Gofukakusa to Emperor Gokomatsu). After the fall of the Kamakura Bakufu, the Kenmu Restoration took place for a while. However, after the civil war that followed, two Imperial Courts stood at the same time in the period of the Northern and Southern Courts (Japan), and they were taken under control by the Northern Court, which was the side of the Ashikaga Shogunate, absorbing the Southern Court. Around this period, the Emperor's loss of power was remarkable, and the 3rd Shogun of Muromachi Bakufu, Yoshimitsu ASHIKAGA, is said have planned to take over the Imperial throne by making his son, Yoshitsugu ASHIKAGA, heir, but since the death of Yoshimitsu, when the Imperial Court tried to give the honorable title Daijo Tenno to Yoshimitsu, the 4th Shogun of Muromachi Bakufu, Yoshimochi ASHIKAGA, strongly refused to accept this (it is said that it was because he didn't like his father since Yoshimitsu cared more about Yoshitsugu than himself), the truth is not yet certain. At the end of the Sengoku Period (Period of Warring States) (Japan), the destitution of the Emperor and Kuge in Kyoto was remarkable, like some Kuge begged by putting his formal headwear for court nobles upside down and some Kuge going to public bathhouse, but it was continued as a system because of the intentional protections of the Emperor and Kuge in both political and economical ways made by powerful Sengoku-daimyo (Japanese territorial lord) and the government by Nobunaga ODA.

The early-modern times

In the Edo period, the Emperor did not hold actual political power, and had an economical base of only 10,000 koku (unit for measuring land in Japan) (later 30,000 koku) of territory. Also because of Kinchu Narabini Kuge Shohatto (a set of regulations that applied to the Emperor and Kuge), his speech and behavior were also strictly limited. It is believed also that the target of respect was pointed at the daimyo and Seii Taishogun (Ue-sama, Shogun-sama), and the Emperor and Kuge were given respect only because of their indirect relationship with common people. However, even though Kuge had lost their actual power, they strived to elevate the authority of the Emperor as the main branch of a family in cultural activities such as sado (tea ceremony) and haikai (seventeen-syllable verse), and starting with the final authority to decide the name of era when changing it, all official court ranks of shogun and daimyo were ceremoniously granted by the Emperor, and the Emperor was an existence having important meaning as the source of authority (against this fact, the bakufu also tried to reduce the Emperor's authority to being ceremonious by intervening in changing the name of the era and personal matters).
In the latter Edo period, Emperor Kokaku tried to give a posthumous title to his father, Kaninnomiya Imperial Prince Sukehito, and this came into conflict with Sadanobu MATSUDAIRA of the bakufu, who opposed that there is no precedent of giving a title to one who was not enthroned as the Emperor, and this was called the Songo Ikken (honorific title incident),

However in the latter half of the eighteenth century, a theory called Taisei Inin Ron, that says people must obey the shogun since the power of Seii Taishogun is entrusted by the Emperor, was proposed in the learned society, and the nature of the authorities of both shogun and the Emperor had begun to be reconsidered. These activities lead to the Sonno Joi Undo (activities to revere the Emperor and expel the barbarians) at the end of Edo period.

The Meiji Restoration

When the shogunate system started to waver, both the Edo Bakufu and the anti-bakufu forces planned to use the authority of the Emperor, and as a result, the authority of the Emperor was heightened. As for the visit of the Matthew PERRY's fleet, the bakufu could not correspond on their own, and reported it to the Imperial Court. There was no precedent like this. From this incident the authority of the Emperor was restored, but at first, the bakufu tried to stop the criticism from anti-bakufu forces by carrying out Kobu-gattai (reconciliation between the Imperial Court and the shogunate). However, this plan failed, and the anti-bakufu forces, mainly Satsuma and Choshu, tried to begin overthrowing the shogunate. The Bakufu forestalled them by conducting Taisei Hokan (transfer of power back to the Emperor), but the shogun was forced to conduct Jikan-nochi (returning of all government posts and territories), and the old shogunate army that was discontented about that, and then collided with the Imperial army in the Battle of Toba-Fushimi, and the civil war began. By that process, in Hakodate, Hokkaido, a republic was declared for a while by Takeaki ENOMOTO ('the Ezo Republic'). The Ezo Republic' elected their president (sosai), but was soon subjugated by the Imperial army.

Toshimichi OKUBO and others, who succeeded to overthrow the bakufu through this Boshin War, at first managed the new government, with the Emperor at center, by the Daijokan (Great Council of State) system of Kyoto. However, when Taisuke ITAGAKI and others, who resigned from the post of Sangi (councilor) after the political change of Seikanron (debate about the subjugation of Korea), started the Jiyuminken Undo (the Freedom and People's Rights Movement), that movement developed gradually into a movement by the people to establish the Diet, and the government promulgated the Constitution of the Empire of Japan and established the Diet and the cabinet system. With this, the system of the Imperial Household adopted a Prussian style constitutional monarch, but the Imperial House Act, which was established at the same time with the Constitution of the Empire of Japan, was considered as 'the family codes of the Imperial Household,' that could not be changed nor abandoned by the cabinet or the Diet, and the system of the Imperial Household began to be used as a system of divine right to reign over the people. There are many scholars that define this system of Imperial Household as the system of absolutism by the Emperor, which holds absolute powers that are isolated from the people.

Further about the system of the Imperial Household, the word 'Tennosei' (Emperor system) is used generally, but Tennosei is originally a word for the Comintern, and it is not appropriate for it to be used as a historical term.

After Meiji period

In 1898, Yukio OZAKI, the Minister of Education in the first Okuma Shigenobu Cabinet, made a speech in an educational meeting, attacking the greed of the domain clique by saying 'If a republic is established in Japan, Mitsui and Mitsubishi would be the president.' and this became a problem, because making an assumption of a republic under the system of Imperial Household was disrespectful, and he was forced into resignation (Kyowaenzetsu Jiken, or republic speech incident). It is said that there was a plan by the anti-Okuma force, the Taro KATSURA group, in the background, but Tsuyoshi INUKAI was appointed as the next Minister of Education. In 1911, the Taigyaku Jiken (a case of high treason) was developed and was used as an excuse to oppress socialists by the government at that time, and 12 people, including Shusui KOTOKU, were executed for attempting to assassinate Emperor Meiji. This incident also shocked many cultivated people at that time. Roka TOKUTOMI wrote 'Muhonron' (on rebellion) and advocated not to be afraid to rebel and Takuboku ISHIKAWA declared war against the 'situation of exclusive period,' but Kafu NAGAI intentionally kept his distance of social interests on this occasion.
After that, the existence of the Emperor was used to evade public criticism against the government's policy, and since speeches and writings criticizing the Emperor were strictly punished, criticism against the Emperor vanished, and came to be called 'the period of winter.'

After that, going through two campaigns to defend constitutionalism, the press became active, and this is also known as Taisho democracy. During the period of Taisho democracy, ideas such as Minponshugi, or a democratic interpretation of Tennosei in liberalism, by Sakuzo YOSHINO appeared. However in 1925, the Maintenance of Public Order Law was proclaimed along with the Universal Manhood Suffrage Act, and speeches and activities containing changes of national polity were prohibited. In 1935, Tatsukichi MINOBE emphasized the theory of the Emperor as an organ of government, which was the mainstream in the learned society, and was denounced in the House of Peers, his books became prohibited, he was prosecuted for lese majesty, and he resigned from the members of the House of Peers. The existence of the Emperor was greatly used as a means to suppress criticism by public opinion against the government and the military.

After the Great Depression, based on the May 15th and February 20th Incidents, the military gained power and greatly utilized the existence of the Emperor. In the Constitution of the Empire of Japan, the supreme command of the military was given to the Emperor, not to the government, and using that as a reason, the military ignored governmental policy and became involved in the Manchurian and other incidents. The sacred and inviolable nature of the Emperor was also emphasized, the government was pressured, and using the rule that Military ministers were officers on active-duty, incidents violating supreme command, and declarations of proved national polity, strengthened the military's power. Around this period, scholars of historic studies of Ancient Japan, like Sokichi TSUDA, were forced to resign simply because he regarded myths to be different from historical facts. It was at the time of the Pacific War that authority reached its peak, and after the period when the National General Mobilization Act was issued in 1938, the Emperor was deified as Arahitogami, and the system of the nation under war with the Emperor in the center was established by the military (refer to Kokoku Shikan, or Emperor-centered historiography which is based on state Shinto). Around this period, like the Nazis in Germany and the Benito MUSSOLINI government in Italy, Fascist systems were established, and because the Tripartite Pact between Japan, Germany, and Italy was formed, the system of Imperial Household at this time was called Tennosei Fascism.

After the end of the World War II

After the end of the World War II, between the countries of the UN, the opinion to punish the Emperor for militarism and abolish Tennosei was strong, but because the Japanese government strongly advocated the preservation of the Emperor, General Douglas MACARTHUR and the General Headquarters of the Allied Powers (GHQ/SCAP), to smoothly advance the administration of occupation and as a bulwark against communism, took the direction that the Imperial Household system should be preserved. There were strong opinions to pursue the responsibility of the war for Emperor Showa, but because of America's diplomatic stratagem, the occupation authorities decided not to do so. Various opinions about the Emperor arose in between the people at that time, and even Sokichi TSUDA and others, who had suffered from Kokoku Shikan (Imperial view of Japanese history), declared not to deny the existence of the Emperor. Other than that, opinion advocating abolishment of the Emperor and theory which states the revision of the name of era by the abdication of Emperor Showa and enthronement of the Crown Prince is appropriate, were advocated by Shigeru NANBARA, Soichi SASAKI, Yasuhiro NAKASONE, and others, but were backed by only some of the people. Emperor Showa showed his intension to abdicate at first, but because of strong opposing opinions, which suggest that abdication would admit the responsibility of the war, withdrew his intention.

After this, a photograph with Generall MACARTHUR, the Commander for the Allied Powers, and Emperor Showa standing side by side (at right) was placed in the newspapers. The photograph of the Emperor, who was considered as Arahitogami and his photographs were called 'Goshin-ei' (honorific name for the photograph of the Emperor) and so on, standing straight without moving next to the relaxed General, placed commonly in newspapers shocked the common people. Further, the Emperor announced the declaration as a human, and inside that, so called 'Ningensengen' (declaration as human), which states that 'the Emperor is human and is not Arahitogami,' was declared. There was a theory stating that this declaration, seen as denying that, "Japanese people are a perfect race in position to rule the world," which was promoted to the people before and during the war through textbooks of 'Shushin' (moral training), etc., and having a 'Charter Oath of Five Articles' declared at the beginning of Shosho (Imperial edict), not necessarily denied completely the way the Emperor existed in the past. However, by opening "Sokkin Nisshi" (the diary of a close associate of the Emperor) by Deputy Grand Chamberlain of the Imperial Household, Michio KINOSHITA, to the public, it was made clear that the Emperor denied himself as 'Arahitogami,' and the scholar insisted such opinions have disappeared.

Emperor Showa, after declaring himself as a human, started Junko (visit by the Emperor) to various places in Japan, but Okinawa, where the Battle of Okinawa took place causing great casualties, and was placed under direct control of the Allied Forces, apart from Japan at that time, was not included. This 'Junko' was welcomed in each place, but in 1947, because welcoming the Emperor had awoken apprehension about the revival of the Emperor's political powers, movements were made by GHQ to stop Junko for a year (there were many people hoisting national flags even though it was prohibited by GHQ). Further, it is said that there was also anticipation of people forming a consciousness of the Emperor as the new symbol to be respected as an object of this Junko. It seemed that the visit to Okinawa was Emperor Showa's dearest wish, and was mentioned during his illness in his later years. Emperor Showa. Detailed in E8.A1.8C.E5.B9.B8.

The Emperor and foreign countries

During the Imperial funeral of Emperor Showa, the heads and leaders of 163 countries of the world, and concerned people of 17 international organizations attended. India mourned for 3 days, and Bhutan mourned a month (Japan mourned for 2 days). Also, when Imperial Prince Akihito was enthroned as Emperor, many leaders of countries around the world attended.

There is an episode (from the book by Kenichi TAKEMURA) that USA Gerald Rudolph Ford's legs trembled when he stood in front of Emperor Showa.

On the other hand, Emperor Showa is seen with hatred from the countries such as Netherlands and Great Britain, who were enemies during World War II. There was a time when Emperor Showa visited the Netherlands, where Molotov cocktails were thrown, etc. by some of people as a protest.

The Emperor has close friendships with the Kingdom of Thailand and the Royal Family of Bhutan.

Disputes over the right of succession to the Imperial Throne.

Since the male Imperial Family was not born from the birth of Imperial Prince Akishino-no-miya Fumihito in 1965 through the birth of Imperial Prince Hisahito in 2006, males in the male line, who could succeed the Imperial Throne, is in short supply, and there is a possibility of the extinction of the Imperial line because heir to the Imperial Throne, as regulated in the Imperial House Act, no longer exists. Because of that, disputes have broken out over whether to revise the Imperial House Act and give a female in female line the right of succession to the Imperial Throne, or keep the male line of succession by returning the former Imperial Family as the Imperial Family again.

Disputes over national structure

Since in the Constitution of the Empire of Japan, the Emperor was in a position to control the right to rule, but against that, in the Constitution of Japan, is a symbol of Japan and the unity of the Japanese people and has also adopted the principle of sovereignty with the people, disputes over whether or not the national structure of Japan changed by the establishment of the Constitution of Japan, broke out. Especially the dispute between Odaka and Miyazawa and the dispute between Sasaki and Watsuji are well known.

The Emperor as the head of nation and amendment of the Constitution

Drafts of Constitutional revision by the Liberal Democratic Party of Japan, by Mr. Hatoyama of the Democratic Party of Japan, by Mr. Ozawa of the Democratic Party of Japan, and by the Institute for International Policy Studies, which has 6 government offices as its authorities in charge and in which former Prime Minister Nakasone belongs, suggests the Emperor to become to be the head of the nation. As for the Constitution Research Council of the House of Representatives and the Constitution Research Council of the House of Councilors, which both neither having the right to propose a bill, it is still argued about the position of the Emperor, and they have not reached a conclusion yet. Draft of Constitutional revisions by the Yomiuri Shimbun mentions that the Tennosei should maintain its form.