Ryoto Tetsuritsu (両統迭立)

"Ryoto tetsuritsu" refers to the situation where the family line of a country's monarchy is split into two and the monarch is alternately selected from these two family lines. The Imperial family (at that time called 'Oke') during the Kamakura period was split into two family lines and was best known to be in the state of Ryoto tetsuritsu regarding the succession of Chiten (retired emperor who runs the cloistered government) and Emperor.

Ryoto tetsuritsu during the Kamakura period
The Ryoto tetsuritsu in this period was between the Jimyoin line, descendants of Emperor Gosaga's third son, Emperor Gofukakusa, and the Daikakuji line, descendants of fourth son Emperor Kameyama.

Beginning
In 1242, Gosaga became Emperor, abdicated the throne to Crown Prince Hisahito (Gofukakusa, aged 4) and started a cloister government in 1246, and then in 1258, without waiting for Gofukakusa to have a prince, installed Gofukakusa (aged 16)'s younger half brother, Tsunehito (Kameyama, aged 10), as Crown Prince and in 1259, he made Gofukakusa abdicate so Tsunehito could become Emperor. Gofukakusa later had sons, and in 1268, Gosaga installed Kameyama's heir (second prince) Yohito (aged 2) as Crown Prince instead of Gofukakusa's heir (second son) Hirohito (aged 4).

From this string of actions, it is easy to presume that Gosaga wanted Kameyama and his descendants as his successors, but Gosaga died in 1272 without clarifying his wishes (aged 53). His will only specified the division of property without naming a successor, only indicating his wish that the naming the next Chiten should follow the wishes of the Kamakura bakufu (Japanese feudal government headed by a shogun). Since both Gofukakusa and Kameyama wanted to be the next Chiten and a fight broke out, the bakufu was asked to make a ruling. The bakufu asked Omiyain, who was the first wife and biological mother of Gofukakusa and Kameyama, which of the sons was the deceased choice and Omiyain gave Kameyama's name, who was subsequently named as Chiten. The reason why Gosaga took such an unclear stance was based on his own experience as being unexpectedly selected from a collateral family line to ascend to Emperor due to the bakufu's intervention, and knew well that if he named a successor that was not to the bakufu's liking, it would easily have been changed by the bakufu. Kameyama attended to government affairs for a short period as Emperor and then abdicated the throne in 1274 to Crown Prince Yohito (aged 8, Emperor Gouda).

On the other hand, Gofukakusa, who lost the position of Chiten, even though he was the older brother, became frustrated and when Gouda became Emperor, he declined the position of Daijo Tenno (the retired emperor) and tried to become a priest as a sign of protest. Amongst the extensive Imperial private estates, Gosaga had planned so that Gofukakusa could inherit the large Chokodo group of private estates consisting of over 100 estates around the country, but Gofukakusa was not satisfied. Later the Chokodo estates became an important financial foundation for the Jimyoin line. Kameyama also inherited the large Hachijoin private estate group consisting of over 200 estates and this became the main financial foundation for the Daikakuji line. The two Imperial lines fought fiercely over not only the positions of Chiten, Emperor, and Crown Prince, but also the Imperial private estates separately managed by nyoin (title given to some high-ranking female Imperial family member who have been Empress, etc.) and other Imperial family members, leading to a division within the Imperial family, both financially as well as politically. Due to Gofukakusa's dissatisfaction, the bakufu intervened and in 1275, named Hirohito (aged 11) as Crown Prince and guaranteed Gofukakusa would be Chiten in the future. Other than the explanation for this intervention that has been given since it happened that the Regent Tokimune HOJO sympathized with Gofukakusa's situation ("Masukagami" (The Clear Mirror)), it has been pointed out that the Kanto Moshitsugi, Sanekane SAIONJI, who was in the position to mediate between Tokimune and the Chiten, was more intimate with the Gofukakusa father and son than the Kameyama father and son and could have worked for a more advantageous solution for Gofukakusa. At this point, the regent family had already split within the bakufu, and it is said that there were intentions to split the Imperial family in the same way (Kazuto HONGO), but there are no historical documents to prove this and the truth is unknown. It is also necessary to note that in the Kamakura period, the Imperial court society in general had a tendency to produce branch families. In any case, due to the intervention of the bakufu in 1275, it was determined that both Gofukakusa and Kameyama had equal right to have their descendants as Emperor and both had eligibility to become Chiten themselves, and this was the beginning of the division of the Imperial family which lasted for two hundred years.

Establishment
Kameyama worked extensively to arrange a court management system within the Imperial court, and established "Koanreisetsu" (Koan Shosatsurei) to maintain class order within the Imperial Court society. This period is called the 'Koan no tokusei' (political reforms in Koan era). At the same time, the bakufu had political reforms led by Yasumori ADACHI, it is thought that there was a close relationship between virtuous governments in both Imperial and Military courts due to the fact that there were cultural exchanges at the individual level between Kameyama and Yasumori.

However, in 1285, Yasumori and his group members were killed and exiled in a coup d'etat by TAIRA no Yoritsuna (Shimotsuki Incident) leading to a change in direction of bakufu measures that affected the Imperial Court, stunning the Kameyama Cloistered Government. Around this time, Gofukakusa schemed, lodging a complaint to the bakufu that Gosaga did not name Kameyama as his heir. In the midst of political unrest, when Kameyama was rumored to be thinking of overthrowing the Shogunate, the bakufu ordered a change in Chiten and Emperor in 1287, with the Crown Prince Hirohito (aged 23, Emperor Fushimi) ascending the throne and Gofukakusa starting a cloistered government. In 1289, also by designation of the bakufu, Fushimi's first son, Tanehito (aged 2) was installed as Crown Prince and during the same year, Gofukakusa's son Imperial Prince Hisaaki was greeted as the head of the Kamakura Shogunate. After witnessing this, Gofukakusa retired and became a priest in 1290 (aged 48), also yielding the job of Chiten to Fushimi. At this point, Ryoto tetsuritsu had not yet completely embedded itself, and the aristocracy did not yet create factions so the aristocrats who served the Daikakuji line Chiten worked for the subsequent Jimyoin line Chiten, leading to the sudden decline of the Daikakuji line. Kameyama was disappointed and became a priest in 1289 (aged 41), and was accused of being involved in an incident where bushi Tameyori ASAHARA and others who lost their territory during the Shimotsuki Incident, invaded the Imperial Palace and tried to assassinate Fushimi, and had to submit an appeal to the bakufu to clear his name in 1290.

When Fushimi became Chiten, he worked diligently for advancement and continued to expand the court management system and actively recruited without bias towards family lineage. The most famous person that Fushimi recruited was Tamekane KYOGOKU. Tamekane was trusted by Fushimi and was the leader of the leading tanka (short poem) circle other than the Nijo school, and was also heavily involved in government affairs. However, Tamekane's individualistic character made many enemies and together with Fushimi's progressive governing stance, it led to confrontation with Sanekane SAIONJI and called attention from the bakufu. In 1298, Fushimi abdicated in favor of the Crown Prince Tanehito (aged 10, Emperor Gofushimi), but a comeback by the Daikakuji line that Sanekane also participated in was staged regarding the nomination of the next Crown Prince. As a result, Gouda's first son, Kuniharu (aged 14) was named as the next Crown Prince. Fushimi continued to attend to government affairs, but the government did not stabilize and the bakufu ordered a change in Chiten and Emperor in 1301, with the Crown Prince Kuniharu (aged 17, Emperor Gonijo) ascending the throne and Gouda starting a cloistered government.

This change is the first time when Ryoto tetsuritsu was announced as being the official policy of the Kamakura Shogunate (when its supreme leader was Tokuso Sadatoki HOJO). The bakufu continued this policy until it fell. There are two opposing theories, one that this was done to establish a division in the Imperial family, and the other is that it was done to avoid direct intervention and leave the Imperial succession to the autonomy of the Imperial family. As Ryoto tetsuritsu became established, aristocrats that served only one of the Imperial lines started to appear, and the Chiten side also asked that of its aristocrats. While the division of the Imperial family led to the division of Imperial Court society in general, the subordination of the aristocrats to the Chiten side also progressed. Since the high officials and important positions were all changed when the heads were changed, confusion such as the judgment of a court cases during a Chiten in one line being easily upturned by the other line's Chiten occurred and this led to a decline in the Imperial Court's authority.

Based on the policy of Ryoto tetsuritsu, the next Crown Prince was to come from the Jimyoin line. The 13 year old Gofushimi had no princes and therefore Fushimi's fourth son, Tomihito (aged 5) became Crown Prince. The possibility of further division threatened and Fushimi took measures to make Tomihito as Gofushimi's adopted heir. Although the Daikakuji line already had its future heir apparent for the throne because Gonijo's first son, Imperial Prince Kuniyoshi was born in 1300, Kameyama was partial to his son Imperial Prince Tsuneaki who was born in 1303, and had made Gouda and Fushimi promise to place Tsuneaki instead of Kuniyoshi on the throne, which led to further seeds of Imperial lineage division.

In 1304, Gofukakusa died at 62, and in 1305, Kameyama died at 57, and Ryoto tetsuritsu entered its second generation. Gouda also attended to government affairs diligently to strengthen the claims of his Imperial line. He was also a devout follower of Shingon Esoteric Buddhism and became a monk in 1307 (aged 41). This was not only meant as a personal religion, but intended to strengthen the legitimacy of the royal line by religious authority. However, in 1308, Gonijo (aged 24) died suddenly and the Crown Prince Tomihito (aged 12, Emperor Hanazono) ascended the throne and Fushimi started a cloistered government. The Crown Prince was to come from the Daikakuji line, but Gouda chose not his direct grandson Kuniyoshi (aged 9), but his second Prince Takaharu (aged 21). This choice took into account the youth and poor health of Kuniyoshi and was a measure to suppress the force that was demanding Tsuneaki as Crown Prince, but in conclusion this only led to make the problem even more complex. In 1313, Fushimi became a priest and yielded the government affairs as Chiten to Gofushimi.

As Ryoto tetsuritsu became established and both lines were able to govern as long as they could wait, the next thing that happened was that they tried to move that event forward. This was specifically accomplished by sending special envoys to the Kamakura Shogunate to appeal for the abdication of the current Emperor. Especially around this time, Fushimi was held in suspicion from the bakufu continuing on from his first cloistered government, and there were even rumors that he was thinking of going against the bakufu and he submitted a official document appealing to the bakufu about his innocence in 1316. As expected, the pressure exerted by the Daikakuji line demanding a change in Chiten/Emperor grew. The bakufu struggled to handle the issue and in 1317, it indicated that the next succession was to be decided by discussion between the two lines and prohibited the sending of special envoys. At the discussion, Gouda demanded that Hanazono abdicate in favor of the Crown Prince Takaharu, and place Kuniyoshi as the next Crown Prince. Fushimi accepted the abdication of Hanazono, but wanted Gofushimi's first son Kazuhito (aged 5) as the next Crown Prince. The discussions broke up, but the power balance between the two lines changed when Fushimi died at 53 in the same year. Gouda demanded Hanazono's abdication again, and Gofushimi could not go against this, so in 1318, the Takaharu (aged 31, Emperor Godaigo) ascended the throne and Kuniyoshi (aged 19) became the Crown Prince. As an exchange condition, Gouda promised Gofushimi that Kazuhito would become the next Crown Prince after Kuniyoshi. Ryoto tetsuritsu was now established as a given. With Godaigo's accession, Gouda's cloistered government was reinstated, but Gouda himself became further devout in esoteric Buddhism and became the chief priest himself by establishing Daikakuji Temple Monseki and he started to let the reins go with government affairs as his health declined along the years, relinquishing the duties as Chiten to Godaigo in 1321 and he died at the age of 58 in 1324. Ryoto tetsuritsu entered into its third generation.

End
Gouda considered Kuniyoshi as his genuine successor and the accession of Godaigo was only an "interim" measure until Kuniyoshi came to age. In the property allocation list for the Daikakuji line written by Gouda, he wrote that Godaigo's descendants had no right to succession and Godaigo should consider Kuniyoshi as his own son and this was also known to those concerned.
In a memorandum left by a person associated with the Jimyoin line at that time expresses Godaigo's position as a 'One-generation head.'
Godaigo was in a position where he could not express all of the authority given to him as Emperor. Hanazono of the Jimyoin line was also in a similar "interim" position, but through the wishes of Fushimi, Hanazono was considered as his older brother Gofushimi's son and called the 'heir' of the Jimyoin line and Gofushimi's son Kazuhito was made Hanazono's son, and Hanazono was fitted into the direct descendant line to save face. Since he also had a mild personality, Hanazono accepted his position and in fact spent much of his energy in nurturing Kazuhito. However, Godaigo was very dissatisfied with his position and became rebellious. There are even some researchers (Yoshihiko AMINO and Shigeaki MORI) who think that Gouda relinquished his government affair duties as Chiten to Godaigo in 1321 because of strong pressure from Godaigo.

Such feelings of Godaigo are expressed on how extensively he developed his policies after starting to take up governmental affairs. Naturally, Godaigo worked on the court management system, speedy court case processing and recruitment of useful human resources that past Chiten had worked on, but he also worked on financial measures such as Koshu-ho (Law defining the price of rice and sake), Jiguchisen-ka to Rakuchu (extra tax on houses and fields in central Kyoto) but he also tried to enlarge the power base of the Imperial Court itself by actively working on areas that the authority of past Chiten did not reach and issued Rakuchu Shuroyaku Fuka-rei, Shinjin Koji Teishi-rei, Sekishoteishi-rei, etc.

However, such new measures naturally did not attain sufficient results because of resistance from aristocrats, large temples and shrines that had their privileges infringed upon and the restrictions imposed by the bakufu, which was strengthening its character as a united national government. Additionally, Godaigo was isolated within the Imperial Court and there were insufficient human resources to work as his hands and feet. The aristocrats that have established the lineage (lineage of reputable families) of who becomes Tenso, Bugyo, and other practical positions in the court management system of the Imperial Court that had been worked on since the cloistered government of Gosaga, had already tied master-subordinate relationships with one of the Imperial lines. Aristocrats subordinate to the Jimyoin line naturally did not cooperate with Godaigo, but many of the aristocrats subordinate to Daikakuji line preferred the direct descendent Kuniyoshi to the 'One-generation-head' Godaigo. Those who worked for Godaigo were people who had a personal relationship with him through study, arts, religion, etc., and were mainly people who were descended from lower class families who wanted their family lines to become premier lineages.

Not being able to accept that he was in the position of a 'One-generation-head' and not being to sufficiently implement his idealized measures, he selected the path of destroying the existing political order by force as a way of breaking out. In those times, the will of parents regarding inheritance had absolute effectiveness and even the court at the bakufu or Imperial court could not easily upturn that decision. It was difficult to change the succession plan for the Imperial Throne that was determined by Gouda using normal measures.
Since Ryoto tetsuritsu was a bakufu policy, it was natural that the bakufu was included as Godaigo's offensive target

It was September, 1324 when Godaigo's first armed bakufu overthrow plan was uncovered. The death of Gouda was in June 1324, so the timing was as if he had waited for his father's death. Since in December of that year the name of the year was changed to Seichu, so this is called the "Seichu Incident." The plan was leaked to the bakufu and some participating members were killed, while some were arrested, but in the end, only Godaigo's aide, Suketomo HINO was exiled to Sado among the Imperial Court relations and Godaigo was not accused of any crimes.

Kuniyoshi was not on friendly terms with Godaigo and since the Seichu Incident, he had appealed to the bakufu to have Godaigo abdicate as soon as possible, but he died suddenly in 1326 (at age 27). The position of Crown Prince was fought over by Kazuhito, the direct heir of the Jimyoin line, Kunimi, who was the younger brother with the same mother of Tsuneaki and Kuniyoshi Shinno who lost their chances to become Crown Prince after Gonijo died, and Godaigo's first son, Imperial Prince Takayoshi, and in the end, Kazuhito (aged 14) was designated Crown Prince by the bakufu's ruling. Kuniyoshi also left a young son, and he was also in a position to be a strong rival of Godaigo in the future, and the position of Godaigo as a 'One-generation-head' was becoming even clearer under the authority of the bakufu and his tendency towards overthrowing the bakufu became stronger.

The second armed bakufu overthrow plan was also discovered beforehand in 1331. On this occasion the bakufu took strong measures. Although Godaigo decided to lead a military uprising earlier than planned (Genko Incident), the bakufu started to arrest related people and moved large forces to suppress the revolt, so Godaigo eluded arrest by escaping Kyoto and joined his rebel army. The bakufu controlled Kyoto and immediately deposed Godaigo in absentia and Crown Prince Kazuhito (aged 19, Emperor Kogon) ascended the throne. Godaigo changed the name of the era to "Genko" in August just before his escape from Kyoto, but the bakufu did not recognize this change and continued to use the previous name, "Gentoku." Shortly, Godaigo was captured and exiled to Oki as a traitor, following the example of Jokyu Disturbance. Participating princes and aristocrats were also severely punished with punishment including execution.

Upon the ascension of Kogon, Gofushimi started a cloistered government. The first thing that Gofushimi started was the selection of the next Crown Prince. Although it was not impossible for the Jimyoin line to monopolize the throne since the Daikakuji line was in a devastated state with Kuniyoshi's early death and Godaigo's rebellion, Gofushimi was true to the principle of Ryoto tetsuritsu in accord with the bakufu's wishes. He asked the widow of Kuniyoshi, Baishi (princess of Gouda) to recommend the next Crown Prince as the acting head of the Daikakuji line. Baishi recommended Kuniyoshi's first prince, who was treated coldly by Godaigo, not allowed to have the coming-of -age ceremony until 12 and not yet officially named. The prince was named Imperial Prince Yasuhito by the Jimyoin line and was also made Imperial Prince. Baishi was given the position Nyoin (Sumeimonin) befitting her rank as the family head of the Daikakuji line, giving her a rank similar to Retired Emperor. Under the regency of Sumeimonin, Yasuhito became Crown Prince and the Daikakuji line was reestablished with the support of the Jimyoin line.

After the Genko Incident ended in failure, guerilla like resistance continued under Godaigo's son, Imperial Prince Moriyoshi and Masashige KUSUNOKI, and gradually the size and region increased until it was a true insurrection. In 1333, Godaigo escaped Oki and stayed at Hoki, indicating his wishes to directly participation the insurrection and widely made a call for participation among the armed groups around the country. The bakufu moved a large force lead by Takaie NAGOE and Takauji ASHIKAGA, adding more soldiers in the Kinki region to contain the insurrection, but Takaie died in battle shortly after arriving in Kyoto and Takauji answered Godaigo's call to join the insurrection force. The effect that the Ashikaga clan, who were a prominent vassal of the Shogun after the Hojo clan in lineage and power, defected from the bakufu was very large and the insurrection rapidly engulfed the whole nation, with the Kamakura bakufu quickly reduced to disintegration.

The person who filled the gap in power was Godaigo, who was still in Hoki. Godaigo issued orders before his return to Kyoto and erased all political actions by the Imperial Court after the Genko Incident. It was natural that government affairs by Gofushimi were terminated and Kogon was deposed, but Godaigo did not even recognize that he was deposed in 1331, and took the stance that he was ruling during the whole time he was exiled in Oki, so therefore there was "no accession nor rule" of Kogon. Godaigo knew well that Gouda's will was still in effect and if he recognized that he had abdicated, he might lose eligibility to rule as Chiten or pass the throne on to his descendants. It was clearly indicated that Kogon was given the title and privileges of the retired emperor but not as preferential treatment for being the former Emperor, but as a prize for refraining the position of Crown Prince. This was a measure to prevent Kogon from ruling as Chiten in the future. Gofushimi abandoned hope for the future and became a priest. Yasuhito was deposed as Crown Prince and even the title of Imperial Prince was taken away. The name of the era was changed and "the second year of Seikei" became "the third year of Genko." The next year, 1334, saw Godaigo's son Imperial Prince Tsuneyoshi (aged 12) as Crown Prince and the position of the Jimyoin line as a Emperor's line was completely negated, and here the Ryoto tetsuritsu that spanned three generations and continued over 50 years came to an end.

Sequel
Even though Ryoto tetsuritsu ended, the concept still remained for a while. The new Godaigo government collapsed in 1336 due to Takauji ASHIKAGA's defection and the cloistered government by Kogon was initiated by Takauji's request (Gofushimi died in the same year at 49), and Kogon's brother Toyohito (aged 16, Emperor Komei) ascended the throne and the Crown Prince was not the deposed prince Yasuhito or Kogon's first son Prince Okihito (aged 3), but Godaigo's son Imperial Prince Nariyoshi (aged 12). Godaigo was officially given the title and privileges of the retired emperor as the previous Emperor and Godaigo had the possibility of ruling as Chiten in the future. These measures were taken under the wishes of Takauji, who wanted to extract concessions from Godaigo and have him cooperate with Takauji's new government, but Godaigo refused any compromises and immediately escaped Kyoto to establish his own imperial court in Yoshino. The Imperial family made a clear transition from the Ryoto tetsuritsu era to the Northern and Southern Dynasties era. Nariyoshi had no value and was deposed as Crown Prince and in 1338, Okihito (aged 5, later Emperor Suko) was made Crown Prince.

The concept of Ryoto tetsuritsu was again brought up upon the union of Northern and Southern Dynasties that Yoshimitsu ASHIKAGA concluded in 1392. Ryoto tetsuritsu, after unification between the descendants of Emperor Gokomatsu of the Northern Dynasty and Gokameyama of the Southern Dynasty, was included as one of the unification conditions.

However, judging from the power balance of both Southern and Northern Dynasties at that time, not only the Northern Dynasty but also the Southern Dynasty probably did not think this condition would be followed and in reality, it was not. However, this condition served as a reason for former Southern Dynasty Imperial family descendants and related people to continue on with resistance and insurrections against the Muromachi bakufu for around 100 years. This activity is called the second Southern Dynasty.

Ryoto tetsuritsu during the Heian period
Ryoto tetsuritsu occurred twice during the Heian period.

Tetsuritsu between Saga line and Junna line
Emperor Kanmu, who established Heian-kyo, had many wives, concubines, and princes, and princesses, but the three princes that were thought to be in an advantageous position for Imperial succession were Ate, Kamino, and Otomo. Their mothers were all from the Fujiwara clan or related family who were empress or received similar treatment, and due to the wishes of Kanmu, they all had wives that were Imperial Princesses and their half-sisters with a different mother (Ate had two wives, Imperial Princess Asahara and Imperial Princess Oyake, Kamino had Imperial Princess Takatsu, and Otomo had Imperial Princess Koshi). What the true wishes of Kanmu were by taking such measures that might lead to a complex competition for the Imperial succession by intentionally lining the three princes is unknown. First, the first prince Ate was instated as Crown Prince in 785. He ascended the throne upon Kanmu's death in 806 as Emperor Heizei, and placed his brother Kamino, who shared the same mother, as Crown Prince. Heizei was not able to ignore the authority and existence that Kamino and Otomo had, because Asahara and Oyake did not have any children and all the other princes had lowly-born mothers.

Heizei had spent a long time as Crown Prince and had a certain degree of ideas about how to govern. Rather than wait until the year after the preceding Emperor died to change the name of the era which was the custom, the new Emperor changed the era name into Dodai and tightened the budget that had loosened while Kanmu had conducted frequent military activity against the Siberian invasion and moved the capital, and actively worked on organizing redundant court positions, placing of a Kansatsushi, where Daijokan directly watches over regional government and abolishing Sangi, but he was sickly from a young age and abdicated the throne to the Crown Prince Kamino (Emperor Saga) in 809. Saga already had a son with Takatsu called Imperial Prince Nariyoshi, but Nariyoshi had a severe physical and mental congenital disability and was considered to have no possibility of attaining the throne. Otomo had a son with Koshi called Imperial Prince Tsuneyo, but Heizei ignored the existence of the Otomo father and son and explicitly placed his son, Imperial Prince Takaoka as Crown prince.

After abdicating and becoming the Retired Empreor, Heizei returned to his birthplace, Heijo-kyo, and when his health recovered slightly, he returned to ruling and started to use the rights of an emperor on his own accord. Originally, a retired empreor was considered to hold the same and equivalent authority as an emperor, so it was considered natural that the retired emperor and emperor rule together since the first Retired Emperor Jito and Emperor Monmu. However, this only functions smoothly when the retired emperor is a direct ancestor or equivalent to the emperor, but it only led to political confusion and conflict between Heizei and Saga because they were half brothers. When in the next year, 810, Heizei commanded Saga to relocate the capital to Heijo-kyo, Saga decided to raise a coup d'etat. Heizei was surprised at the turn of events and tried to make a comeback by escaping to the East Country, but was blocked by armed forces sent by Saga and defeated, he then relinquished all authority and became a priest. Takaoka was stripped of his position as Crown Prince and also became a priest.

Saga installed Otomo instead of Takaoka as Crown Prince. Although Saga did not have any sons to select as Crown Prince anyway, it was a measure to respect the authority and existence of Otomo. There was also the circumstance that Otomo supported Saga in the conflict with Heizei. Saga paid great care in reconciling between brothers and tried to respect Otomo's position as much as possible so as not to repeat the conflict with Heizei that ended in armed confrontation. One sign was to wed his princess, Imperial Princess Masako to Otomo, but the most significant was when he abdicated the throne to Otomo in 824, he declined the position of Retired Emperor even if it was a position automatically assumed to be taken up by the abdicating emperor. After his abdication, he returned to his status as one of the Imperial family members, and publicly announced that he left all power to the coming Emperor Otomo (Emperor Junna). Of course Junna who accepted the abdication did not accept this, and after serious discussions between the two, it was decided in the end that Saga was to decline the position of retired emperor and then Junna was to present the title and privileges of retired emperor to Saga. This led to a change in the position of retired emperor as a position to be given by the coming emperor, and established the superiority of the residing emperor, relieving the harmful effects of diarchy/dual power.

The reconciliation and mutual concession continued on, and was emphasized at every occasion. Upon the ascension of Junna, the prince Masara, who was born between Saga and Empress TACHIBANA no Kachiko, became Crown Prince. In 833, Junna abdicated the throne to the Crown Prince Masara (Emperor Ninmyo) and here the declination of retired emperor by Junna and empress dowager by Empress Masako and the refusal by the new Emperor Ninmyo was repeated, and the Crown Prince was decided to be the prince born between Junna and Masako, Imperial Prince Tsunesada (Koshi and Tsuneyo had already died young).

However, such relationship between Saga and Junna was only a personal relationship of trust and was not accepted widely among the aristocracy. Rather, the aristocracy even showed a tendency to break apart into Saga group and Junna group. When Junna died in 840 and Saga fell into critical condition in 842, this break up became apparent. First, it is said that Togu-bo Tachihaki, TOMO no Kowamine and Tajima no Gon no kami (Provisional Governor of Tajima Province), TACHIBANA no Hayanari visited Heizei's son, Imperial Prince Abo and tried to convince him to go to the East and lead an insurrection. Abo had a bitter experience when his father was deposed and sent to Kyushu as Dazai gon no sochi (Provisional Governor-General of the Dazai-fu offices), did not follow their advice and immediately reported this to Kachiko, who was the Grand Empress Dowager at that time. Meanwhile, Saga passed away. Kachiko informed Ninmyo via Chunagon (vice-councilor of state), FUJIWARA no Yoshifusa and the arrest and punishment of associated people began. Kowamine and Hayanari both denied the charges but were exiled and aristocrats close to Junna were dismissed from office, and finally, Tsunesada was deposed as Crown Prince to take joint responsibility and he became a priest as Takaoka did in the past. This incident is the "Jowa Incident." Since the positions of the chief plotters, Kowamine and Hayanari, were so low (and also from branch lines of lineages that would not even be a target for 'elimination of other clans by the Fujiwara clan') for planning such an insurrection and the people who were punished for being associated with the plan had no motives, there is a theory that proposes that the whole incident was made up. In any case, the next Crown Prince was Ninmyo's first son, Michiyasu (later Emperor Montoku), and the Imperial line was united to the descendants of Saga. This incident was also the opportunity for Michiyasu's mother, FUJIWARA no Junshi's older brother Yoshifusa to grab hold of power.

Tetsuritsu of Reizei line and Enyu line
As soon as Emperor Murakami ascended in 946, he placed a Crown Prince as soon as his second son Norihira was born in 950. Whereas the first son Imperial Prince Hirohira was born in the same year to Chunagon FUJIWARA no Motokata's daughter, FUJIWARA no Sukehime, Norihira's mother was Udaijin (minister of the right) FUJIWARA no Morosuke's daughter, FUJIWARA no Anshi. As a result, Murakami selected Morosuke as the maternal relative for the next Emperor. In 958, Anshi became Empress because she was the Crown Prince's mother and also was Murakami's favorite. Norihira married Imperial Princess Shoshi, the only daughter of Emperor Suzaku, who was the emperor before Murakami, and strengthened his position. However, as he grew up, the mental state of Norihira was altered and he started to show signs of madness. However, since he was the first son of the Empress and the son-in-law of the previous Emperor, with support from influential maternal relatives, Murakami could not make the decision to disinherit Norihira. Murakami died in 967, and Norihira ascended the throne at 18 (Emperor Reizei).

Reizei's madness was already apparent to everyone and it was predicted from the beginning that his rule would be short. Other than Shoshi who became Empress, Reizei had various wives such as FUJIWARA no Koretada (FUJIWARA no Motokata's first son)'s daughter, FUJIWARA no Kaishi, but there were no sons yet and the selection of a Crown Prince was of immediate concern. In this case, the candidates are Reizei's half-brothers. There were two candidates, Tamehira, who was 2 years younger, and Morihira, who was 9 years younger. In the end, Morihira was named Crown Prince in 967. The usual theory is that the Fujiwara clan aristocrats did not want Tamehira since he was MINAMOTO no Takaaki's son-in-law, but there is also the theory that it was taken into consideration that if Tamehira, who is close in age with Reizei was selected as Crown Prince, the rule of Reizei may be too short (Michihisa HODACHI).

In 968, Kaishi gave birth to Reizei's first prince, Morosada. This in fact shortened the period until the abdication of Reizei. Because now there was a chance for Reizei's descendants to continue the Imperial line even after Reizei's abdication. In 969, Reizei abdicated the throne to Crown Prince Morihira (Emperor Enyu) and Morosada became the next Crown Prince. Enyu was an "interim" Emperor, similar to Hanazono and Godaigo in the later Kamakura period.

However, in Reizei and Enyu's case, different from Hanazono and Godaigo, father Murakami, mother Anshi, male relative Morosuke were all dead and there was no guardian to control the Imperial succession. By this time, Morosuke's younger bother Morotada, older brother, FUJIWARA no Saneyori, first son Koretada, had died consecutively and a situation were the aristocrats in the generation of children of Saneyori, Morosuke, Morotada fought amongst themselves to obtain the position as the next maternal relative. In this situation where there was a power vacuum, Enyu attracted attention as a candidate to establish a new Imperial lineage and was able to obtain wives with high lineage who could become empress and give birth to a crown prince, such as FUJIWARA no Kanemichi (Morosuke's second son)'s daughter, FUJIWARA no Koshi,FUJIWARA no Yoritada (Saneyori's first son)'s daughter, FUJIWARA no Junshi, FUJIWARA no Kaneie (Morosute's third son)'s daughter, Higashisanjyoin and also the support of influential maternal relatives. Enyu also wanted to establish his own imperial line and after the death of the first Empress Koshi, skipping Senshi who was the mother of the prince Yasuhito, he made the childless Junshi Empress and acted as if he was leading the aristocrats around.

This behavior made father Kaneie and daughter Senshi angry, leading to Senshi leaving the Imperial Palace and Kaneie's family boycotting administration duties. As a result of the confrontation, Enyu and Kaneie reached a compromise. It was for Enyu to abdicate and place Yasuhito as Crown Prince. Enyu was able to escape the position of "interim" by establishing his descendants as successors to the Imperial title and Kaneie was able to become the maternal grandfather to a crown prince. This was a compromise that had large benefits to both sides.

Hence in 984, Enyu abdicated the throne to Crown Prince Morosada. The next Crown Prince was Yasuhito. Morosada (Emperor Kazan)'s maternal grandfather Koretada had already died and Yoritada who had no maternal relative relations was Kanpaku (chancellor), he actively ruled without delegation to the Kanpaku with Koretada's first son, FUJIWARA no Yoshichika and son of his nurse, FUJIWARA no Korenari. New political measures such as the termination of creating new private estates, promotion of circulation of coinage, public determination of selling prices, etc. were announced.

However, perhaps Kazan inherited his father's blood, but he had an abnormal personality. This was especially apparent with his relationship with women. He became extremely and abnormally attached to a certain woman, eventually getting sick of her and then he would be attracted to a different woman, and this cycle went on. In 986, Nyogo (a consort of an emperor) FUJIWARA no Shishi (daughter of FUJIWARA no Tamemitsu), who had all of Kazan's attention at that time, died of disease. It is said that Shishi was pregnant and wanted to go back to her parent's home to have the baby, but Kazan forcefully kept her in court, which led to her getting ill and eventually dying. The sadness of Kazan was abnormal and he even thought about becoming a priest and retiring from the world. With the solicitation of Kazan's childhood friend FUJIWARA no Michikane (Kaneie's third son), Kazan finally decided on becoming a priest, escaping the court in the cover of darkness and went to Gankei-ji Temple (Kazan-ji Temple) in Yamashina, Kyoto together with Michikane to have his head shaved. By becoming a priest, Kazan was automatically considered to have abdicated. Michikane's activity was obviously planned together with his father Kaneie, and the path to Gankei-ji Temple was guarded by bushi sent by Kaneie, and if Michikane was about to be made a priest with Kazan, the bushi were supposed to rescue him by force. Kaneie himself arrived in the middle of the night at the Imperial Palace without its emperor to quickly do the administrative work necessary for abdication and the next morning, he had the Crown Prince Yasuhito (Emperor Ichijo) ascend to the throne. Kaneie was the new Emperor's maternal grandfather and became regent instead of Yoritada.

Ichijo was 7 years old and obviously did not have a son, and since Ichijo was Enyu's only son, the Crown Prince had to be selected from among Reizei's sons, and because Reizei's second son, Okisada, whose mother was Kaneie's daughter FUJIWARA no Choshi, a Ryoto tetsuritsu situation arose. Okisada was 4 years older than Ichijo and was ridiculed as 'Ro-togu' (elderly crown prince). Kaneie was both the Emperor and Crown Prince's maternal grandfather and had obtained absolute power. Enyu also obtained a certain degree of political clout by being the young emperor's father, leading to a "cloistered government"-like situation.

Kaneie in 989, Enyu in 990 died consecutively and there was a situation of "no guardian" similar to that immediately after Enyu's ascension to the throne. The circumstance was different in that Ichijo's mother Senshi was still healthy. Kaneie's first son FUJIWARA no Michitaka took Kaneie's place and even though for a while he acted with absolute authority such as there being no opening as empress but forcibly making his daughter FUJIWARA no Teishi as Empress, he died in 995, and his heir Michikane died about one month after Michitaka, leaving Michitaka's heir, FUJIWARA no Korechika and Kaneie's fourth son FUJIWARA no Michinaga to fight over the position of family head. In the end, Michinaga, who had Senshi's support, gained the position and became Nairan (position allowing first glance of any documents to be sent to the emperor). Michinaga later sent Korechika away as Dazai gon no sochi seizing the opportunity of Korechika's misconduct and had his daughter Jotomonin (Shoshi) become Ichijo's Empress, consolidating his power.

While the political scene was centered with Ichijo, Crown Prince Okisada was isolated and it was clear that Reizei line was the inferior Imperial line. Neither his father Reizei, who was mad, nor his older brother Kazan, who had lost interest in politics and dabbled in religion, but also enjoyed taking pleasures and philandering, were able to offer any support. Okisada had FUJIWARA no Naritoki (Morotada's first son)'s daughter, FUJIWARA no Seishi and Michitaka's daughter, FUJIWARA no Genshi as wives, but Naritoki and Michitaka both died in 995, and Okisada had no influential maternal relative for support. In addition, Genshi died in 1002 without any children. Okisada had to wait for 25 years before accession because Ichijo waited for Shoshi, who entered the court when she was 11, to have a prince.

In 1011, Ichijo was nearing death and finally abdicated the throne to the Crown Prince Okisada (Emperor Sanjo). The next Crown Prince was Shoshi's second prince Atsunari. Michinaga had obtained the position of maternal grandfather of the next emperor and wished for the early abdication of Sanjo, hence the relationship between the two was rocky. On the other hand, Michinaga tried to have his daughter FUJIWARA no Kenshi as Sanjo's Empress and this did not improve their relationship because Sanjo respected FUJIWARA no Seishi, who he had been together for a long time. In the end, taking the past case where Ichijo had both Teishi and Shoshi as Empress, Seishi and Kenshi were both to become Empress, but reflecting the all mighty authority of Michinaga and the weak power base of Sanjo, not only was Kenshi was first to become Empress and then Seishi, but although many aristocrats cooperated actively for the ceremony for the making of Kenshi as Empress, Seishi's ceremony was met with sabotage by Michinaga and not attended by many aristocrats, angering Sanjo and his aides.

Eventually, Sanjo suffered from an eye disease and Michinaga started to clearly suggest abdication to Sanjo, and in 1016, Sanjo reluctantly abdicated to the Crown Prince Atsunari (Emperor Goichijo) because his decrease in eyesight started to infringe upon governing duties and daily life. Due to the strong wishes of Sanjo, the Crown Prince was Sanjo and Seishi's first son, Koichijoin.

Atsuaki became Crown Prince, but as with his father he suffered from pressure from Michinaga and isolation within the political field. In 1017, when Sanjo died, Atsuaki decided to refrain from being the Crown Prince. This was not an act of escapism but a political trade-off. Atsuaki indicated the exchange conditions to obtain treatment equivalent to that of the Retired Emperor and also becoming Michinaga's son-in-law in exchange for the position of Crown Prince, and got Michinaga to agree before leaving the position of Crown Prince. This promise was kept and Atsuaki was given the title 'Koichijoin' equivalent to the Retired Emperor, received Nenkan, Nensyaku and had a In-cho (office) similar to the Retired Emperor. Additionally, Michinaga's daughter, FUJIWARA no Kanshi became Koichijoin's Nyogo. Instead, Goichijo's younger half-brother (Shoshi's son), Atsunaga (later Emperor Gosuzaku), who was also one of Michinaga's grandchildren, became Crown Prince. This is how Ryoto tetsuritsu ended with Michinaga's authority and power putting pressure on the Imperial Court and the Imperial line was united with Enyu's descendants.

There were no further Emperors made from the Reizei's Imperial line, but the blood line continued through the maternal side of the family and affected the family in later years. Komyomonin born between Sanjo and Kenshi became Crown Prince Atsunaga's wife and she gave birth to the second prince Takahito. Takahito after his father Gosuzaku's death was made Crown Prince for his older half brother Emperor Goreizei, and when Goreizei died without a son, he became Emperor (Emperor Gosanjo). This title after death 'Gosanjo' is said to have been chosen by himself while he was alive to mean that he was the heir of his maternal grandfather, Sanjo ("A Tale of Flowering Fortunes"). Additionally, one of Gosanjo's wives was Koichijo's son, MINAMOTO no Motohira's daughter, MINAMOTO no Kishi, and she gave birth to his second prince, Imperial Prince Sanehito (Heian period) and third prince, Imperial Prince Sukehito. Sanehito became Crown Prince upon the accession of his half brother Emperor Shirakawa, but died early without a chance to ascend to the throne. Sukehito was considered a replacement for his half brother Sanehito did not become Crown Prince, but under the protection of his long-lived grandmother Teishi (Komyomonin), at one time he was influential in the political field as a rival candidate for Emperor against Shirakawa and his son Emperor Horikawa.

Ryoto tetsuritsu in countries other than Japan
Kuwait, a small country located at the far end of the Persian Gulf is a monarchy with the House of Al-Sabah ruling as chief (Emir). The first Sabah selected as Emir since the country was built at its present location was 1756. Originally under the suzerainty of the Ottoman Empire, in 1899, the seventh Emir Mubarak decided to escape the control of the Ottoman Empire by becoming a protectorate of the British Empire. Mubarak is considered to be a wise lord for leading the restoration of the House of Al-Sabah and is respectfully called "Paramount Chief." Later in 1961, it escaped the protection of the United Kingdom and became an independent country.

After Mubarak, his first son Jabir became the eighth, his second son Salim became the ninth and Jabir's son, Ahmad became the tenth chief. Later, it became tradition to alternate the post of Emir between the descendants of Jabir and the descendants of Salim. The lineage of the past Emirs are as follows.

The tenth chief Ahmad: Jabir line
The eleventh chief Abdullah: Salim line
The twelfth chief Sabah: Salim line
The thirteenth chief Jabir: Jabir line
The fourteenth chief Saad: Salim line
The fifteenth chief Sabah (current Emir): Jabir line

In 2006, the Chief Jabir died after a long period of battling disease, and although the Crown Prince Saad became chief, he was also elderly and sick and was not in any condition to conduct the duties as chief. In recent years, in the Kuwait political field, Jabir line royal family members had superiority over Salim line members, and upon Saad's ascension, there was a voice mainly from the Jabir line royal family members for Saad to abdicate because of his not being able to execute his duties. Instead, Sabah, a royal member of the Jabir line who had the actual power of national government working in place of the sick Chief Jabir and Crown Prince Saad as Prime Minister, was nominated. In Kuwait, the Prime Minister is considered the most likely candidate as the next Crown Prince. Salim line royal members naturally were against this, and there were efforts to reach a compromise between the two lines, but the talks ended in breaking up and the government run by the Jabir line submitted a bill to dismiss the chief to the congress, which has the right to dismiss the chief. The congress unanimously decided on dismissing the Chief and named Sabah as the new Chief. In an attempt to deflect the dishonor of being dethroned, Saad submitted a document regarding voluntary abdication to the congress, but this was not voted on in time. Saad's tenure as Chief was only 10 days.

After Sabah became Chief, he named his younger half brother Nawaf, who has the same father, as Crown Prince and his nephew Nasser as Prime Minister, and major positions are taken up by the Jabir line. In the future, the post of Chief is expected to be monopolized by the Jabir line and it is predicted that the Salim line will decline.