By the 1660s, Alexei's wars with Poland and Sweden had put an increasing strain on the Russian economy and public finances. In response, Alexei's government had begun minting large numbers of copper coins in 1654 to increase government revenue but this led to a devaluation of the ruble and a severe financial crisis. As a result, angry Moscow residents revolted in the 1662 Copper Riot, which was put down violently.