Iwate (岩手郡 Iwate-gun) is a rural district located in Iwate Prefecture, Japan.
As of October 2016, the district has an estimated population of 36,326 and an area of 1404.24 km². The entire city of Takizawa, the southern half of the city of Hachimantai and most of the city of Morioka were formerly part of Iwate District.
The district consists of three towns:
Iwate District was the northernmost of the six districts of northern Mutsu Province (六奥郡)created in the early Heian period after the conquest of the Kitakami River Valley from the Emishi tribes by the Japanese army led by General Sakanoue no Tamuramaro. The districts were named by Emperor Heizei, and the name of “Iwate” was originally written with the kanji 磐手, and appears in this form in the Yamato Monogatari, compiled in the year 951. By the middle Heian period, the kanji had changed to its present form, although it was also occasionally referred to as ‘Iwadenomori' (岩出の森郡)
Iwate District was the northern frontier of Japan until the Enkyu-Emishi War of 1070, which extended the frontier to the northern coast of Honshu. As with the rest of the region, the early history of Iwate District is uncertain. Although Shiwa Castle was constructed in 803 as a major army base in the region, it fell into ruins only ten years later. The area came to be ruled by the Abe clan until the Former Nine Years War (1051-1063), followed by the Kiyohara clan until the Gosannen War (1083-1089) and the Northern Fujiwara until 1189. During the Muromachi period, the area gradually came under the control of the Nanbu clan from Nukanobu District to the north.