The of Japan is the country's monarch. He is the head of the Japanese Imperial Family. Under Japan's present constitution, the Emperor is the "symbol of the state and the unity of the people," and is a ceremonial figurehead in a constitutional monarchy (see Politics of Japan). The Emperor of Japan is the only current head of state entitled "Emperor".
The role of the emperor of Japan has historically alternated between that of a supreme-rank cleric with largely symbolic powers and that of an actual imperial ruler. An underlying imperial cult (the idea of Arahitogami) regards the emperor as being descended from gods. Until 1945, the Japanese monarchs had always been, officially, the Commander-in-Chief of the forces. However, contrary to Western monarchs, the role had rarely been assumed on the field since the establishment of the first shogunate. Japanese emperors have nearly always been controlled by external political forces, to varying degrees.
Since the mid-nineteenth century, the Imperial Palace has been called "Kyūjō" (宮城), then Kōkyo (皇居), and located on the former site of Edo Castle in the heart of Tokyo. Earlier emperors resided in Kyoto for nearly eleven centuries.
Historically the titles of tennō in Japanese have never included territorial designations as is the case with many European monarchs. The position of emperor is a territory-independent phenomenon - the emperor is the emperor, even if he has followers only in one province (as was the case sometimes with the southern and northern courts).
In 1868 an imperial "restoration" was declared, and the Shogunate was stripped of its powers. The new constitution officially gave executive powers to the Emperor. Article 4 prescribed that "The Emperor is the head of the Empire, combining in Himself the rights of sovereignty, and exercises them, according to the provisions of the present Constitution" while, according to article 6 "The Emperor gives sanction to laws and orders them to be promulgated and executed" and article 11, "The Emperor has the supreme command of the Army and the Navy." During the Shōwa era, the liaison conference created in 1937 also made the Emperor the leader of the Imperial General Headquarters.
Traditionally, the Japanese considered it disrespectful to call a person of noble rank by his given name. This convention has largely died out along with the noble class itself, although it is still observed for the imperial family. Since Emperor Meiji, it has been customary to have one era per emperor and to rename each emperor after his death using the name of the era over which he presided, plus the word Tennō. Prior to Emperor Meiji, the names of the eras were changed more frequently, and the posthumous names of the emperors were chosen in a different manner.
Outside of Japan, beginning with Emperor Shōwa, the emperors are often referred to by their given names, both whilst alive and posthumously. For example, the previous emperor is usually called Hirohito in English, although he was never referred to as Hirohito in Japan and was renamed Shōwa Tennō after his death, which is the only name that Japanese speakers currently use when referring to him.
The current emperor on the throne is typically referred to by the title Tennō Heika (天皇陛下, lit. "His Majesty the Emperor") or Kinjō Heika (今上陛下, lit. "his current majesty") when speaking Japanese. Other terms used to refer to the emperor in Japanese include Heika and Okami, but these are much less typical than Tennō Heika or Kinjō Heika in ordinary conversation. The current emperor will be renamed Heisei Tennō (平成天皇, lit. "Heisei Emperor") after his death and will then be referred to exclusively by that name in Japanese. Non-Japanese speakers typically refer to him now as Akihito, or Emperor Akihito, and will likely continue to do so after his death.
Throughout history, contrary to any sort of harem practice of not recognizing a chief wife and just keeping an assortment of female chattel, Japanese emperors and noblemen appointed the position of chief wife.
The Japanese imperial dynasty consistently practiced official polygamy, a practice that only ended in the Taishō period (1912-1926). Besides the empress, the emperor could take, and nearly always took, several secondary consorts ("concubines") of various hierarchical degrees. Concubines were allowed also to other dynasts (shinno, o). After a decision decreed by Emperor Ichijo, some emperors even had two empresses simultaneously (kogo and chugu are the two separate titles for that situation). With the help of all this polygamy, the imperial clan thus was capable of producing more offspring. (Sons by secondary consorts were usually recognized as imperial princes, too, and could be recognized as heir to the throne if the empress did not give birth to an heir.)
Of the eight female tennō (reigning empress) of Japan, none married or gave birth after ascending the throne. Some of them, being widows, had produced children prior to their reigns.
In the succession, children of the empress were preferred over sons of secondary consorts. Thus it was significant which quarters had preferential opportunities in providing chief wives to imperial princes, i.e. supplying future empresses.
Apparently the oldest tradition of official marriages within the imperial dynasty were marriages between dynasty members, even half-siblings or uncle and niece. Such marriages were deemed to preserve better the imperial blood or were aimed at producing children symbolic of a reconciliation between two branches of the imperial dynasty. Daughters of others than imperials remained concubines, until Emperor Shōmu--in what was specifically reported as the first elevation of its kind--elevated his Fujiwara consort to chief wife.
Japanese monarchs have been, as much as others elsewhere, dependent on making alliances with powerful chiefs and other monarchs. Many such alliances were sealed by marriages. The specific feature in Japan has been the fact that these marriages have been soon incorporated as elements of tradition which controlled the marriages of later generations, though the original practical alliance had lost its real meaning. A repeated pattern has been an imperial son-in-law under the influence of his powerful non-imperial father-in-law.
Beginning from the 7th and 8th centuries, emperors primarily took women of the Fujiwara clan as their highest wives - the most probable mothers of future monarchs. This was cloaked as a tradition of marriage between heirs of two kamis, Shinto gods: descendants of Amaterasu with descendants of the family kami of the Fujiwara. (Originally, the Fujiwara were descended from relatively minor nobility, thus their kami is an unremarkable one in the Japanese myth world.) To produce imperial children, heirs of the nation, with two-side descent from the two kamis, was regarded as desirable - or at least it suited powerful Fujiwara lords, who thus received preference in the imperial marriage market. The reality behind such marriages was an alliance between an imperial prince and a Fujiwara lord, his father-in-law or grandfather, the latter with his resources supporting the prince to the throne and most often controlling the government. These arrangements created the tradition of regents (Sessho and Kampaku), with these positions allowed to be held only by a Fujiwara sekke lord.
Earlier, the emperors had married women from families of the government-holding Soga lords, and women of the imperial clan itself, i.e. various-degree cousins and often even their own sisters (half-sisters). Several imperials of the 5th and 6th centuries were children of a couple of half-siblings. These marriages often were alliance or succession devices: the Soga lord ensured the domination of a prince, to be put as puppet to the throne; or a prince ensured the combination of two imperial descents, to strengthen his own and his children's claim to the throne. Marriages were also a means to seal a reconciliation between two imperial branches.
After a couple of centuries, emperors could no longer take anyone from outside such families as primary wife, no matter what the expediency of such a marriage and power or wealth brought by such might have been. Only very rarely was a prince without a mother of descent from such families allowed to ascend the throne. The earlier necessity and expediency had mutated into a strict tradition that did not allow for current expediency or necessity, but only dictated that daughters of a restricted circle of families were eligible brides, because they had produced eligible brides for centuries. Tradition had become more forceful than law.
Fujiwara women were often Empresses, and concubines came from less exalted noble families. In the last thousand years, sons of an imperial male and a Fujiwara woman have been preferred in the succession.
The five Fujiwara families, Ichijo, Kujo, Nijo, Konoe and Takatsukasa, were the primary source of imperial brides from the 8th century to the 19th century, even more often than daughters of the imperial clan itself. Fujiwara daughters were thus the usual empresses and mothers of emperors.
The acceptable source of imperial wives, brides for the emperor and crown prince, were even legislated into the Meiji-era imperial house laws (1889), which stipulated that daughters of Sekke (the five main branches of the higher Fujiwara) and daughters of the imperial clan itself were primarily acceptable brides.
Since that law was repealed in the aftermath of World War II, the present Emperor Akihito became the first crown prince for over a thousand years to have an empress outside the previously eligible circle.
The Japanese imperial dynasty bases its position in the expression that it has reigned "since time immemorial". It is true that its origins are buried under mists of time: there are no records to show an existence of any early emperor who is known to have not been a descendant of other, yet earlier emperors. An early ancestor of the dynasty, Emperor Keitai (flourished in the early 500's b.c.) however is suspected to have been an homme nouveau, though the sources state that he was a male-line descendant of Emperor Ōjin. According to records, the family he started on the throne, however descends also from at least one, probably of several, imperial princesses of the immediate dynasty of his predecessors. The tradition built by those legends has chosen to recognize just the putative male ancestry as valid for legitimizing his succession, not giving any weight to ties through the said princesses. Millennia ago, the Japanese imperial family developed its own peculiar system of hereditary succession. It has been non-primogenitural, more or less agnatic, based mostly on rotation. Today, Japan uses strict agnatic primogeniture - in other words, pure Salic law. It was adopted from Prussia, by which Japan was greatly influenced in the 1870s.
Strict agnatic primogeniture is, however, directly contradictory to several old Japanese traditions of imperial succession.
The controlling principles and their interaction were apparently very complex and sophisticated, leading to even idiosyncratic outcomes. Some chief principles apparent in the succession have been:
Historically, the succession to Japan's Chrysanthemum Throne has always passed to descendants in male line from the imperial lineage. Generally they have been males, though of the over one hundred monarchs there have been nine women (one pre-historical and eight historical) as Emperor on eleven occasions. See the male line of the Yamato dynasty.
Over a thousand years ago, a tradition started that an emperor should ascend relatively young. A dynast who has passed one's toddler years, was regarded suitable and old enough. Reaching the age of legal majority was not a requirement. Thus, a multitude of Japanese emperors have ascended as children, as young as 6 or 8 years old. The high-priestly duties were deemed possible for a walking child. A reign of around ten years was regarded a sufficient service. Being a child was apparently a fine property, to endure tedious duties and to tolerate subjugation to political powerfuls, as well as sometimes to cloak the real powerful members of the imperial dynasty. Almost all Japanese empresses and dozens of emperors abdicated, and lived the rest of their lives in pampered retirement, and/or influencing behind the curtains. Several emperors abdicated/reached their entitled retirement while still in their teens. These traditions show in Japanese folklore, theater, literature and other forms of culture, where the emperor is usually described or depicted as an adolescent.
Before the Meiji Restoration, Japan had eleven reigns of female tennō, or reigning empresses, all of them daughters of the male line of the Imperial House. None ascended purely as a wife or as a widow of an emperor. Imperial daughters and granddaughters, however, usually ascended the throne as a sort of a "stop gap" measure - if a suitable male was not available or some imperial branches were in rivalry so that a compromise was needed. Over half of Japanese empresses and many emperors abdicated once a suitable male descendant was considered to be old enough to rule (just past toddlerhood, in some cases). Four empresses, Empress Suiko, Empress Kōgyoku (also Empress Saimei) and Empress Jitō, as well as the mythical empress Jingu kogo, were widows of deceased emperors and princesses of the blood imperial in their own right. One, Empress Gemmei, was the widow of a crown prince and a princess of the blood imperial. The other four, Empress Genshō, Empress Kōken (also Empress Shōtoku), Empress Meishō and Empress Go-Sakuramachi, were unwed daughters of previous emperors. None of these empresses married or gave birth after ascending the throne.
Article 2 of the 1889 Meiji Constitution (the Constitution of the Empire of Japan) stated, "The Imperial Throne shall be succeeded to by imperial male descendants, according to the provisions of the Imperial House Law." The 1889 Imperial Household Law fixed the succession on male descendants of the imperial line, and specifically excluded female descendants from the succession. In the event of a complete failure of the main line, the throne would pass to the nearest collateral branch, again in the male line. If the empress did not give birth to an heir, the emperor could take a concubine, and the son he had by that concubine would be recognized as heir to the throne. This law, which was promulgated on the same day as the Meiji Constitution, enjoyed co-equal status with that constitution.
Article 2 of the Constitution of Japan, promulgated in 1947 by influence of the US occupation administration and still in force, provides that "The Imperial Throne shall be dynastic and succeeded to in accordance with the Imperial Household Law passed by the Diet." The Imperial Household Law of 16 January 1947, enacted by the ninety-second and last session of the Imperial Diet, retained the exclusion on female dynasts found in the 1889 law. The government of Prime Minister Yoshida Shigeru hastily cobbled together the legislation to bring the Imperial Household in compliance with the American-written Constitution of Japan that went into effect in May 1947. In an effort to control the size of the imperial family, the law stipulates that only legitimate male descendants in the male line can be dynasts; that imperial princes and princesses lose their status as Imperial Family members if they marry outside the Imperial Family; and that the Emperor and other members of the Imperial Family may not adopt children. It also prevented branches, other than the branch descending from Taishō, from being imperial princes any longer.
Until the birth of Prince Hisahito, son of Prince Akishino, on September 6, 2006, there was a potential succession crisis, since Prince Akishino was the only male child to be born into the imperial family since 1965. Following the birth of Princess Aiko, there was some public debate about amending the current Imperial Household Law to allow women to succeed to the throne. This creates a logistical challenge as well as political: any change in the law would most likely mean a revision to allow the succession of the first born rather than the first-born son; however, the current emperor is not the first born--he has elder sisters. In January 2005 Prime Minister Junichiro Koizumi appointed a special panel composed of judges, university professors, and civil servants to study changes to the Imperial Household Law and to make recommendations to the government.
The panel dealing with the succession issue recommended on October 25, 2005 amending the law to allow females of the male line of imperial descent to ascend the Japanese throne. On January 20, 2006, Prime Minister Junichiro Koizumi devoted part of his annual keynote speech to the controversy, pledging to submit a bill allowing women to ascend the throne to ensure that the succession continues in the future in a stable manner. However, shortly after the announcement that Princess Kiko was pregnant with her third child, Koizumi suspended such plans. Her son, Prince Hisahito, is the third in line to the throne under the current law of succession. On January 3, 2007, Prime Minister Shinzo Abe announced that he would drop the proposal to alter the Imperial Household Law.