Russo–Swedish War (1656–1658)

The Russo-Swedish War of 1656–1658 was fought by Russia and Sweden against the background of the simultaneous Northern Wars and the War for Ukraine. Despite initial successes, Tsar Alexis of Russia failed to secure his principal objective — to revise the Treaty of Stolbovo, which had stripped Russia of the Baltic coast at the close of the Ingrian War.

When Charles X of Sweden invaded Poland, captured Warsaw and announced his claims on the Russian conquests in the orbit of the Grand Duchy of Lithuania, Afanasy Ordin-Nashchokin (who led Russian diplomacy at the time) decided it was an opportune time to suspend hostilities against the weakened Polish-Lithuanian Commonwealth and to attack the rear of the Swedish Empire instead. To that end he opened negotiations and concluded a truce with Poland in summer 1656, a move which enraged a major ally of Russia, Ukrainian hetman Bogdan Khmelnytsky who maintained good relations with Sweden and was fighting against Poland.

In July, a reserve force of the Russian army struck across Swedish Ingria and overran two key Baltic fortresses — Nöteborg and Nyen. A separate detachment advanced on Tartu, which fell in October. The main forces marched along the bank of the Western Dvina towards Riga, taking Daugavpils and Koknese on their way. By the end of August, the capital of Livonia was besieged and bombarded.

As Russia had no full-fledged navy to intercept reinforcements coming to the Swedish garrison across the Baltic, Riga managed to hold out until October, when foreign officers commanding a small Russian flotilla defected to the other side and the Russians had to lift the siege. In the aftermath of this reverse, the Swedes recaptured much of Ingria, took the Pskov Monastery of the Caves and inflicted a heavy defeat on the Russian general Matvey Sheremetev at Valki in 1657.

By the end of 1658, Denmark was knocked out of the Northern Wars and the Ukrainian Cossacks under Khmelnytskyi's successor, Ivan Vyhovsky, allied themselves with Poland, changing the international situation drastically and inducing the tsar to resume the war against Poland as soon as possible. Under such circumstances, it was necessary to bring the Swedish adventure to a speedy end. On 20 December Ordin-Nashchokin negotiated with Sweden the Treaty of Valiesar, whereby Russia was allowed to keep the conquered territories in present-day Latvia and Estonia — Koknese, Aluksne, Tartu, Syrensk — for three years.

When the term expired, Russia's military position in the Polish war had deteriorated to such a point that the tsar could not allow himself to be involved into a new conflict against powerful Sweden. His boyars had no other choice but to sign in 1661 the Treaty of Kardis, which obliged Russia to yield its Livonian and Ingrian conquests to Sweden, confirming the provisions of the Treaty of Stolbovo. This settlement was observed until the Great Northern War broke out in 1700.