Emperor Kanmu in the context of "Taira"

Heian-kyō (平安京; lit. "peaceful/tranquil capital") was one of several former names for the city now known as Kyoto. It was the de jure capital of Japan for over one thousand years, from 794 to 1868 with an interruption in 1180.

Emperor Kanmu established it as the capital in 794, moving the Imperial Court there from nearby Nagaoka-kyō at the recommendation of his advisor Wake no Kiyomaro and marking the beginning of the Heian period of Japanese history. According to modern scholarship, the city is thought to have been modelled after the urban planning for the Tang dynasty Chinese capital of Chang'an (modern-day Xi'an). It remained the chief political center until 1185, when the samurai Minamoto clan defeated the Taira clan in the Genpei War, moving administration of national affairs to Kamakura and establishing the Kamakura shogunate.

Kyoto (/ki.ˈoʊ.toʊ/ or /ˈkjoʊ.toʊ/; Japanese: 京都, Kyōto [kʲoꜜː.to] ), officially Kyoto City (京都市, Kyōto-shi; [kʲoː.toꜜ.ɕi] ), is the capital city of Kyoto Prefecture in the Kansai region of Japan's largest and most populous island of Honshu. As of 2020, the city had a population of 1.46 million, making it the ninth-most populous city in Japan. More than half (56.8%) of Kyoto Prefecture's population resides in the city. The city is the cultural anchor of the substantially larger Greater Kyoto, a metropolitan statistical area (MSA) home to a census-estimated 3.8 million people. It is also part of the even larger Keihanshin metropolitan area, along with Osaka and Kobe.

Kyoto is one of the oldest municipalities in Japan, having been chosen in 794 as the new seat of Japan's imperial court by Emperor Kanmu. The original city, named Heian-kyō, was arranged in accordance with traditional Chinese feng shui following the model of the ancient Chinese capitals of Chang'an and Luoyang. The emperors of Japan ruled from Kyoto in the following eleven centuries until 1869. It was the scene of several key events of the Muromachi period, Sengoku period, and the Boshin War, such as the Ōnin War, the Honnō-ji Incident, the Kinmon incident, and the Battle of Toba–Fushimi. The capital was relocated from Kyoto to Tokyo after the Meiji Restoration. The modern municipality of Kyoto was established in 1889. The city was spared from large-scale destruction during World War II and, as a result, its prewar cultural heritage has mostly been preserved.

The Nara period (奈良時代, Nara jidai; Japanese pronunciation: [na.ɾa (d)ʑiꜜ.dai]) of the history of Japan covers the years from 710 to 794. Empress Genmei established the capital of Heijō-kyō (present-day Nara). Except for a five-year period (740–745), when the capital was briefly moved again, it remained the capital of Japanese civilization until Emperor Kanmu established a new capital, Nagaoka-kyō, in 784, before moving to Heian-kyō, modern Kyoto, a decade later in 794.

Japanese society during this period was predominantly agricultural and centered on village life. Most of the villagers followed Shintō, a religion based on the worship of natural and ancestral spirits named kami.

The Imperial Court in Kyoto was the nominal ruling government of Japan from 794 AD until the Meiji period (1868–1912), after which the court was moved from Kyoto (formerly Heian-kyō) to Tokyo (formerly Edo) and integrated into the Meiji government. Upon the court being moved to Kyoto from Nagaoka by Emperor Kanmu (737–806), the struggles for power regarding the throne that had characterized the Nara period diminished. Kyoto was selected as the location for the court because of its "proper" amount of rivers and mountains which were believed to be the most auspicious surroundings for the new capital. The capital itself was built in imitation of Chang'an, the Chinese capital of the Tang dynasty, closely following the theories of yin-yang. The most prominent group of people within the court was the civil aristocracy (kuge) which was the ruling class of society that exercised power on behalf of the emperor.

Kyoto's identity as a political, economic, and cultural centre started to be challenged in the post-1185 era with the rise of the shogunate system which gradually seized governance from the emperor. Minamoto no Yoritomo was the first to establish the post of the shōgun as hereditary, receiving the title in 1192. After Yoritomo launched the shogunate, true political power was in the hand of the shōguns, who were mistaken several times for the emperors of Japan by representatives of Western countries. The Kamakura shogunate (or Kamakura bakufu) would go on to last for almost 150 years, from 1185 to 1333.

Wake no Kiyomaro (和気 清麻呂; 733–799) was a high-ranking Japanese official during the Nara period. He was born in Bizen Province (now Wake, Okayama) to a family of politically important, devoted Buddhists who hoped to keep Buddhism and politics separate through religious reform. He became a trusted advisor to Emperor Kanmu, a position which he used to encourage the development of Buddhism in a direction which would prevent it from posing a threat to the government. According to the Shoku Nihongi, he was sent to the Usa Shrine to receive a divine message; stating that only those of descent from Amaterasu could become emperor, it refuted the previous divine message claiming Dōkyō was to be the next emperor after Empress Kōken (later Empress Shōtoku). This report angered Dōkyō, who used his influence with the Empress to have an edict issued sending Kiyomaro into exile; he also had the sinews of Kiyomaro's legs cut, and only the protection of the Fujiwara clan saved him from being killed outright.

The following year, however, Empress Shōtoku died. She was succeeded by Emperor Kōnin, who in turn exiled Dōkyō to Shimotsuke Province and not only recalled Wake no Kiyomaro from exile, but also appointed him as both kami (governor) of Bizen Province and Udaijin (junior minister of state). The following year, he petitioned the governor of Dazaifu to send officials to Usa to investigate allegations of "fraudulent oracles"; in his later report, Wake no Kiyomaro stated that out of five oracles checked, two were found to be fabricated. This resulted in the government relieving Usa no Ikemori of his position as head priest and replacing him with the previously-disgraced Ōga no Tamaro. Following this, Wake no Kiyomaro returned to Yamato. He remained a trusted advisor to Emperor Kammu; in the spring of 793, he convinced the emperor to abandon the delay-plagued construction of a capital at Nagaoka and instead seek another location to the northeast, at Heian-kyō (modern-day Kyōto.

The Shoku Nihongi (続日本紀) is an imperially-commissioned Japanese history text. Completed in 797, it is the second of the Six National Histories, coming directly after the Nihon Shoki and followed by Nihon Kōki. Fujiwara no Tsugutada and Sugano no Mamichi served as the primary editors. It is one of the most important primary historical sources for information about Japan's Nara period.

The work covers the 95-year period from the beginning of Emperor Monmu's reign in 697 until the 10th year of Emperor Kanmu's reign in 791, spanning nine imperial reigns. It was completed in 797 AD.