The Sekke (Setsu Family) (摂家)
The Sekke consisted of five families that the main branch of the Fujiwara Family clan had established during the Kamakura era, whereby it achieved the top rank of court nobility kakaku (family status). They were able to be promoted to regent or chief adviser to the Emperor through dainagon (chief councilor of state), udaijin (minister of the right) and sadaijin (minister of the left). The sekke consisted of five families: Konoe, Kujo, Ichijo, Nijo and Takatsukasa. The Sekke is also referred to as the Sekkan Family (Sekkannke), Gosekke (Gosetsu Family) or Shippei Family. The leader of Toshi (Toji) had also been elected from among the five families.
Establishment of the Gosekke (Gosetsu Family)
Through the main branch of the family of FUJIWARA no Yoshifusa of Fujiwara Hokke (Fujiwara Hoku Family), in the early Kamakura period, FUJIWARA no Tadamichi's sons, Motozane KONOE and Kanezane KUJO established the Sekkan Family (Sekkan-ke) of the Konoe group and Kujoryu Sekkan-ke, a regent family, respectively; this resulted in the division of the main branch of the family into two families (although there was, in addition the Matsudono Family of the Sekkan Family (Sekkannke) of the Matsudono group, the originator of which was Motofusa MATSUDONO, who was also a son of Tadamichi; but, the Matsudono Family is not counted as sekke, with the two families because, after Moroie MATSUDONO became regent, no one from the Matsudono Family became a regent or chief advisor of the Emperor and the family line failed many times).
Later, the Konoe Family, which was the main branch, was established from the Sekkan Family (Sekkan-ke) of the Konoe group, and the Takatsukasa Family was established by Kanehira TAKATSUKASA. Furthermore, the Nijo, Ichijo and Kujo families were established by Michiie KUJO's sons Yoshizane NIJO, Sanetsune ICHIJO and Norizane KUJO, respectively, from Kujoryu Sekkan-ke, the regent family.
Additional notes for the above figure: the brothers are shown from the left in their order of seniority.
Taking a position of regent or chief advisor to the Emperor from the family other than Sekke
After the establishment of Gosekke, only a member of the Gosekke could be appointed as regent or chief advisor to the Emperor, meaning that the five families comprising the Sekke dominated the positions of regent and chief advisor to the Emperor. Therefore, Hideyoshi TOYOTOMI tried to take a position as chief advisor to the Emperor (Hideyoshi TOYOTOMI). At that time he called himself TAIRA no Ason but became Yoshi, the adapted child of Sakihisa KONOE in 1585; ultimately, he became FUJIWARA no Hideyoshi and thereby achieved the position of chief advisor to the Emperor. Later, Hideyoshi TOYOTOMI's adopted child, Hidetsugu TOYOTOMI, was appointed as the Emperor's chief adviser under the name of TOYOTOMI no Ason, thus marking the only exception to the tradition that no member of the family other than Gosekke would be appointed as the chief advisor to the Emperor.
The Edo Bakufu and the Sekke
When the Edo bakufu (Japanese feudal government headed by a shogun) was established, it enacted the Kinchu Narabini Kuge Shohatto (Court Noble's Act), whereby the structure in which the appointment of a regent or chief advisor to the Emperor could not be made without a recommendation by the bakufu. On the other hand, the bakufu offered official and unofficial support for the regent, chief advisor to the Emperor and the sekke. As a result, after the Kan-ei period the regent and chief advisor to the Emperor presided over the Imperial Court's decision that the regent and chief advisor to the Emperor were, as a general rule, not able to participate, even in the period of the Sekkan (regent to the Emperor) government; thus any court noble who was from the Seiga Family or another family of lower position would be deprived of the rights of participation and speaking, even if the court noble was a minister. Moreover, in the case where a family line of the Sekke failed, there was an additional provision that only the adopted child from the Imperial Family or the adopted child from the same sekke was allowed to inherit the sekke, and the tacit provision that only the person who once took the position of regent, chief advisor to the Emperor or seii taishogun (literally, "great general who subdues the barbarians") could be appointed as the grand minister of state, whereby court nobles from the Seiga Family and other families of the lower position were expelled from their positions as mainstays of the Imperial Court.
As a result, it became possible to administer the Imperial Court of the Edo period by the agreements of the Gosekke alone, so that it became difficult even for the Emperor to oppose the Imperial Court. Moreover, as long as the bakufu virtually controlled the right of appointment of regent or chief advisor to the Emperor, even the family head of the Gosekke could not oppose the intention of the bakufu, and the system for controlling the Imperial Court, which was the orderly sequence from the bakufu through the sekke/samurai families (five plus four people at most) to the Emperor and each court noble, was thereby established as an extremely efficient system for the bakufu.
Nonetheless, the Emperor and court nobles from families other than the Sekke were not amenable and continued their resistance when the opportunity arose. Their discontent erupted in the form of cloister governments by both former emperors Gomizuno (Emperor/Reigen Emperor), in the Horeki Conspiracy or Songo Ikken (incident) and Demo, of the 88 retainers of the Imperial Court.
After the Meiji Restoration
After the Meiji Restoration, the family head of each family was entitled to be a duke. Moreover, since the Meiji's new administration adopted the system of departments of state, the sekke was no longer appointed as regent or chief advisor to the Emperor. Therefore, the five families after the Meiji era are now generally referred to as 'Old Sekke' or 'Old Sekkan Family,' with the prefix 'Old' as an addition.
According to old Imperial House Act implemented before World War II, a person of royalty or new nobility was qualified to marry a man of royalty, and there existed a consuetude that a legitimate wife of the main branch of the Imperial Family who was a future Empress (i.e., the crown princess) should be limited to a female from royalty or the Old Sekke.