Immediately before the Gangyo War, the increase in the cost of Akita-jo Castle to appease the Emishi in Hokkaido had become a problem, to the extent that the finances of Dewa Province were put under pressure.
元慶の乱が始まる直前に、秋田城の対北海道蝦夷の饗給の増大は、出羽国の財政を圧迫するまでに問題化していたという。