History
* Due to 1878 land reforms, the district was founded when it broke off from the Uwa District. (2 towns, 31 villages) * July 1, 1895 — The village of Tsushima broke up into the villages of Takachika and Iwamatsu. (2 towns, 32 villages) * July 1, 1899 — The village of Kiyomitsu broke up into the villages of Mimaki and Kiyomitsu. (2 towns, 33 villages) * May 1, 1917 — The village of Maruho merged into the town of Uwajima. (2 towns, 32 villages) * October 3, 1919 — The village of Iwamatsu gained town status. (3 towns, 31 villages) * August 1, 1921 — The town of Uwajima and the village of Yawata merged to form the city of Uwajima. (2 towns, 30 villages) * September 1, 1934 — The village of Kushima merged into the city of Uwajima. (2 towns, 29 villages) * February 11, 1938 — The village of Tamajiri merged into the town of Yoshida. (2 towns, 28 villages) * September 10, 1938 — The village of Takachika merged into the town of Iwamatsu. (2 towns, 27 villages) * November 10, 1940 — The village of Akeharu was renamed and gained town status to become the town of Matsumaru. (3 towns, 26 villages) * November 10, 1941 — The village of Asahi was renamed and gained town status to become the town of Chikanaga. (4 towns, 25 villages) * April 1, 1951 — Parts of the village of Kitanada merged into the town of Iwamatsu. * October 10, 1954 — The villages of Mima, Narutae, and Futana merged to become the town of Mima. (5 towns, 22 villages) * February 11, 1955 — The villages of Kiyomitsu, Mimami, Kitanada, Hataji, Shimonada the town of Iwamatsu merged to form the town of Tsushima. (5 towns, 17 villages) * March 1, 1955 — The villages of Tachima, Kisakata, and Okuna merged into the town of Yoshida. (5 towns, 14 villages) * March 31, 1955 **Parts of the village of Takamitsu and the village of Tamatsu from Higashiuwa District merged into the town of Yoshida. **The villages of Takamitsu (excluding parts) and Miura merged into the city of Uwajima. (5 towns, 12 villages) **The villages of Yoshifuji, Aiji, Izumi, Mishima, and the town of Chikanaga merged to become the town of Hiromi. (5 towns, 8 villages) **The village of Yoshinobu and the town of Matsumaru merged to become the town of Matsuno. (5 towns, 7 villages) * January 1, 1957 — The village of Kuno merged into the city of Uwajima. (5 towns, 6 villages) * April 1, 1958 — The villages of Shitaba, Komobuchi, Yusu, Tojima and Hiburijima merged to become the village of Uwaumi. (5 towns, 2 villages) * August 1, 1958 — Parts of the town of Hiromi merged into the town of Mima. * April 1, 1974 — The village of Uwaumi merged into the city of Uwajima. (5 towns, 1 village) * January 1, 2005 — The town of Hiromi and the village of