朝廷迁往长冈京

Emperor Kanmu moved the court from Heijō-kyō at Nara to Nagaoka-kyō in 784. The new site lay near the Katsura–Yodo river system and routes through Yamazaki, giving the court access to waterborne supplies and connections toward the Inland Sea. Fujiwara no Tanetsugu, a senior official, directed the construction.

The project required more than a new imperial residence. Provinces sent tax goods and building supplies to Nagaoka; officials received resources to construct residences, and households whose land fell within the palace site received compensation. The court entered in 784 while building continued. Later proclamations acknowledged the burdens of construction and granted remissions.

Tanetsugu's assassination in 785 and subsequent succession disputes disrupted the governing coalition, but did not immediately end the capital. Nagaoka remained the court's seat until the move to Heian-kyō in 794. Access to transport, the organization of a new court, and the costs of building all belong to its history; distance from Nara's temples alone does not explain the undertaking.