In October 764, Nakamaro attempted a rebellion with the military power he amassed by becoming totoku (Governor General) and Military Chief of Shikinai (four provinces close to the Capital Kyoto; Yamato, Yamashiro, Settsu, Kawachi), Sangen (three major barrier stations), Omi, Tanba, Harima and other provinces, but was foiled by an anonymous report.
天平宝字8年（764年）9月、仲麻呂は都督四畿内三関近江丹波播磨等国兵事使になり軍権を手にして反乱を計画するが、密告により発覚。