NAGAOKA-KYō (長岡京) was the capital of Japan from 784 to 794.
Its location was reported as Otokuni District ,
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,
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
Excavations begun in 1954 revealed the remains of a gate to the imperial residence.