Nagaoka-kyō (長岡京) was the capital of Japan from 784 to 794. Its
location was reported as Otokuni District, Yamashiro Province, and
Nagaokakyō, Kyoto, which took its name from the capital. Parts of the
capital were in what is now the city of Nagaokakyō, while other parts
were in the present-day Mukō and Nishikyō-ku, the latter of which
belongs to the city of Kyoto.
In 784, the
Emperor Kanmu moved the capital from Nara (then called
Heijō). According to the Shoku Nihongi, his reason for moving was
that the new location had better water transportation routes. Other
explanations have been given, including the wish to escape the power
of the Buddhist clergy and courtiers, and the backing of the
immigrants from whom his mother was descended.
In 785, the administrator in charge of the new capital, Fujiwara no
Tanetsugu, was assassinated. The emperor's brother, Prince Sawara, was
implicated, exiled to Awaji Province, and died on the way there.
In 794, Emperor Kammu moved the capital to Heian (in the center of the
present-day city of Kyoto). Reasons cited for this move include
frequent flooding of the rivers that had promised better
transportation; disease caused by the flooding, affecting the empress
and crown prince; and fear of the spirit of the late Prince Sawara.
Excavations begun in 1954 revealed the remains of a gate to the
Japan National Historical Museum exhibit
Capital of Japan
Coordinates: 34°56′36″N 135°42′12″E / 34.94333°N
135.70333°E / 34.94333; 135.70333