thumb|Map of the major sites of Heijō-kyō, with the palace to the north

thumb|250px|A model of the main part of Heijō Palace, a part of the Heijōkyō 1/1000 model held by Nara City Hall. <br/>View from the north.

was the imperial residence in the Japanese capital city Heijō-kyō (today's Nara), during most of the Nara period. The palace, which served as the imperial residence and the administrative centre for most of the Nara period from 710 to 794 AD, was located at the north-central location of the city in accordance with the Chinese models used for the design of the capital.

The palace consisted of a , a large rectangular walled enclosure which contained several ceremonial and administrative buildings, including the government ministries. Inside this enclosure was the separately walled residential compound of the emperor or the Inner Palace. In addition to the emperor's living quarters, the Inner Palace contained the residences of the imperial consorts as well as certain official and ceremonial buildings more closely linked to the person of the emperor.

The original role of the palace was to manifest the centralised government model adopted by Japan from China in the 7th century—the Daijō-kan and its subsidiary Eight Ministries. The palace was designed to provide an appropriate setting for the emperor's residence, the conduct of state affairs, and associated ceremonial functions.

After the capital was moved to Heian, the palace structures were either moved there or suffered several fires and other disasters and disappeared. The site was converted to agricultural use, and almost no trace of it remained; the location was still known, however. Excavations started in the , and large-scale reconstruction based on contemporary literary sources and excavations started in the .

The excavated remains of the palace and the surrounding area were established as a UNESCO World Heritage Site in 1998 along with a number of other buildings in the area, identified collectively as the "Historic Monuments of Ancient Nara."

History

thumb|Miniature model of the former imperial audience hall compound

thumb|Miniature model of the east assembly hall (Choshu-den) of the latter imperial audience hall compound

One year after Empress Genmei's succession to the Chrysanthemum Throne in Keiun 4 (707 AD), a rescript was issued deciding on the move from Fujiwara-kyō near Asuka towards the northern edge of the Nara basin. The new capital city's name was written Heijō (), but also pronounced Nara at the time.

The city, and the palace grounds, was based largely on Chang'an (present-day Xi'an), the capital of China during the Tang dynasty, which was contemporary to the time when Nara was capital. Chang'an was in turn, like many ancient east Asian cities, based on a complex system of beliefs & laws of geomancy. This dictated the grid system of streets, as well as the necessity for spiritually protective shrines or temples to be placed at particular cardinal directions around the city. The city area measured 6 kilometers (3.7 mi) from east to west and 5 kilometers (3.1 mi) from north to south.

In accordance with this system, the palace was placed at the northern end, on an extended line from Suzaku Street, the main thoroughfare running north–south straight through the center of the city. The street ended at the Suzaku Gate, and the rest of the palace buildings were then placed beyond to the north of this gate. The primary buildings of the palace compound were the Daigoku-den, where governmental affairs were conducted, the Chōdō-in where formal ceremonies were held, the Dairi, the emperor's residence, and offices for various administrative agencies.

The Nara period covers 75 years from 710 to 784 AD. Emperor Shōmu moved the capital to other places, such as Kuni-kyō and Shigaraki Palace, in the period between 740 and 745 AD. The imperial buildings and government offices were drastically transformed around this period. In the later Nara period, the audience hall was erected in the eastern part, at the south side of the imperial domicile. This is called the latter audience hall. A number of buildings in the imperial domicile and the government offices were replaced and renovated several times. This was probably not due to the repair of the old buildings but due to another reason.

When the capital was moved to Heian-kyō (now called Kyoto), Nara's Imperial Palace was simply abandoned. Over the ensuing centuries, the ravages of time and the elements slowly destroyed the buildings, until by the beginning of the Kamakura period in the late 12th century there was practically nothing left above ground. However, those sections that lay underground were preserved and later rediscovered by modern archaeologists.

  • Nara Palace Site Museum
  • Heijokyu Imperial Palace, from The Official Nara Travel Guide
  • Official UNESCO page
  • Geomancy and Imperial Position in Nara
  • Excavation report The Comprehensive Database of Archaeological Site Reports in Japan.