Mutsu Province (1868)
On December 7, 1868 (January 19, 1869 in the Gregorian calendar), four additional provinces (Rikuchū, Rikuzen, Iwaki, and Iwashiro) were separated from Mutsu, leaving only a rump corresponding to today's Aomori Prefecture (with Ninohe District of Iwate Prefecture). At the same time, while the characters of the name were unchanged, the official reading was changed to the on'yomi version "Rikuō".
- Aomori Prefecture
- Iwate Prefecture
- Ninohe District (二戸郡)
- Nussbaum, Louis-Frédéric and Käthe Roth. (2005). Japan encyclopedia. Cambridge: Harvard University Press. ISBN 978-0-674-01753-5; OCLC 58053128
- Titsingh, Isaac. (1834). Annales des empereurs du Japon (Nihon Odai Ichiran). Paris: Royal Asiatic Society, Oriental Translation Fund of Great Britain and Ireland. OCLC 5850691.