June 28 – Defeat at Polonka. The army of Prince Ivan Khovansky (about 9,000–10,000 men) was completely routed by the Polish-Lithuanian hetmans Stefan Czarniecki and Paweł Sapieha. This lifted the siege of the town of Lyakhovichi and allowed the Poles to go on the counteroffensive.
September–October – The Chudnov Catastrophe. The largest defeat. The Russian army of Voivode Vasily Sheremetev (about 15,000 men), together with the Cossack army of acting Hetman Tymofiy Tsetsura, was surrounded near Chudnov. After Hetman Yurii Khmelnytsky (son of Bohdan Khmelnytsky) betrayed Moscow and concluded the Slobodyshche Treaty with the Poles, Sheremetev was forced to capitulate on humiliating terms. He spent 20 years in captivity.
Devaluation of copper currency: To cover military expenses, starting in 1656, the government began mass-producing copper coins at the same value as silver ones. By 1660, their value had sharply dropped (requiring an additional payment to the ruble), which led to monstrous inflation and speculation.
Rise of counterfeiting: By 1660, it became clear that the fight against coin counterfeiting had failed. Wealthy people, including relatives of the tsar (his father-in-law, I.D. Miloslavsky), took bribes to protect counterfeiters, which caused great public resentment and prepared the ground for the "Copper Riot" (1662).
Church Council of 1660: This year, a Church Council was held to decide the fate of the disgraced Patriarch Nikon (who had carried out reforms but abandoned his see). The Council resolved to depose Nikon and elect a new patriarch.
Protest of Epiphanius Slavinetsky: The Council's decisions were not implemented due to the sharp protest of the learned hieromonk Epiphanius Slavinetsky, who proved that a trial of the patriarch without the ecumenical hierarchs was illegal. The conflict dragged on until 1666.
1 Kopeck 1660.
Pskov Mint.
