Heian-kyo (平安京)

Heian-kyo (literally "tranquility and peace capital") was the old capital of Japan established by Emperor Kanmu in 794. Also called Heian-jo Castle.

Summary
Heian-kyo was the castle city laid out to be rectangular, of 4.5 km east-west by 2.2 km north-south, built straddling Kadono-no-koori and Otagi-no-koori counties of Yamashiro Province (currently center of Kyoto city, Kyoto Prefecture). The Daidairi (the greater imperial palace) occupied the northernmost central position, and the Suzaku-oji Avenue (main avenue of Heian-kyo) was laid out from there to the center of the city, so as to bisect into Sakyo (left city) and Ukyo (right city) (Sakyo is on the east side and Ukyo is on the west side). This two dimensional plan was basically adopted from the Heijo-kyo and copied the Changan of Chinese Sui/Tang dynasties. There were, however, no fortified walls. It is also said that selection of the location followed beliefs of the Shijinsoo (an ideal topography for the four Taoist gods) of Feng Shui (Chinese geomancy) as learned from China.

The ambit of Heian-kyo was smaller than current Kyoto-city. Ichijo-oji Avenue as the northern limit of the city is the current Ichijo-dori Street between Imadegawa-dori Street and Marutamachi-dori Street. Kujo-oji Avenue as the southern limit is the current Kujo-dori Street located a little south of JR Kyoto station. Togoku-oji Avenue as the eastern border is the current Teramachi-dori Street. The assumed location for the western border, Nishikyogoku-oji Avenue draws a line north-south between the following two stations - Hanazono Station of the JR West Sanin main line (Kyoto pref.) and Nishi-Kyogoku Station of the Hankyu Kyoto main line.

The inner capital was subdivided into 'Machi/Cho' (town) of approx. 120 sq. meter by Oji (main avenue) and Koji (small alley) which ran east-west and north-south.
Machi (Cho) of four rows running east-west (except for the northern two rows) were called 'Jo,' and Machi of four rows running north-south were called 'Bo.'
Each of the sixteen Machi (Cho) belonging to the same Jo and Bo were numbered accordingly.
According to this rule, a town could be called 'Ukyo 5-Jo 3-Bo 14-Cho.'

The width of a road was approx. 12 m, even for Koji (small alleys). Oji (main avenues) were over 24 m. Currently, most roads within Kyoto City are much narrower. Suzaku-oji Avenue had a width of approximately 84 meters. Also, Horikawa-koji Alley and Nishi Horikawa-koji Alley ran parallel to rivers (Horikawa River - Kyoto Pref) and Nishihorikawa River).

History
In 784, Emperor Kanmu relocated the capital to Yamashiro Province and built Nagaoka-Kyo. Apparently, it was to get away from Yamato Province where the nobles and Buddhists who supported the Emperor Tenmu government had gathered, and to build the capital for the new Emperor Tenchi. However, in 794, only 10 years after that, Emperor Kanmu relocated the capital to the north of Yamashiro Province, and Heian-kyo was established. This re-relocation was said to have been caused by a sequence of events, from the assassination of FUJIWARA no Tanetsugu which occurred in Nagaoka-Kyo, to the disinheritance of Imperial Prince Sawara, which also delayed the building of Nagaoka-Kyo and as a result it did not make much progress.

The building of Heian-kyo is presumed to have started from the greater imperial palace (Daidairi), and then continued to the Kyo (urban district). However, the land of Ukyo did not become developed for dwellings even during the 9th century, due to it being a wetland formed by the Katsura-gawa River (of the Yodo-gawa river system). In the 10th century when the Ritsuryo system became a mere façade, the land was desolated and some areas were diverted to farm lands which was, in general, prohibited in Kyo. Residential areas for nobles were established mainly in Sakyo, excepting the northern Ukyo which was close to Daidairi. While residents from the upper nobles, such as the Fujiwara clan, gathered in northern Sakyo, the poor went over to the eastern limit of Heian-kyo and started living next to the Kamo-gawa River (the Yodo-gawa river system). Then the eastern riverside of Kamo-gawa River was built up with temples and second houses, so the urban district spread out to the east. In 980, Rajo-mon Gate (Rasho-mon Gate), located to the southern end of Suzaku-oji Avenue, was blown down, and was never re-built. This was how the Heian-kyo gradually shifted from the original ambit to the east, to the medieval/modern ages town of Kyoto.

Heian-kyo (Kyoto) gradually lost its function as government administrator, by the formation of the Kamakura bakufu or Edo bakufu based in the Kanto Region. At the time of the Meiji Restoration, the relocation of the capital was avoided by Edo becoming Tokyo, but it became the absent capital due to Emperor's imperial stay in Tokyo (please refer to the section of "Tokyo Tento"). After that, the imperial return to Kyoto was postponed. However, the imperial palace was conserved under the order of Emperor Meiji and the Takamikura (Emperor's throne), which indicates the emperor's location, is still located in the Shishinden (Hall for State Ceremonies) inside the Kyoto Gosho (Kyoto Imperial Palace).

Names
Heian-kyo was pronounced as 'Heian-kyo' in On-yomi (Chinese readings) by later generations, but it was originally pronounced as 'Taira no Miyako' in Kun-yomi (Japanese readings).
Usually, the name of the capital was commonly crowned with the name of the place, so it should have been 'Kadono Miyako.'
However, since the turmoil of the Nagaoka-Kyo, previously mentioned, was one of reasons for relocation, they wished the name to have 'Heian' (Kun-yomi 'Taira') (peace and tranquility) to avoid the new capital having any bad luck.

Schematic diagram of Heian-kyo (temporary)

Heian Capital Relocation Memorial Activities

Heian Shrine, Jidai Festival (1100th Anniversary, 1895)
Kyoto Station/Kyoto Municipal Subway Tozai Line/Nijo Station -Godaigo Station (1200th Anniversary, 1997)

Other

Nakuyo (794) Uguisu Heian-kyo' (Singing nightingale of Heian-kyo) were the highly famous rhyming words for the year.

The Kyoto City Heiankyo Sosei-Kan Museum exhibits the reconstructed model of Heian-kyo (1/1000, Kyoiki/Oto/Kitayama areas), the reconstructed model of Buraku-den Hall (1/20), the reconstructed model of the Shibi at Buraku-den Hall (life size) and many other excavated articles from the Heian period.