Battle of Vilnius (1655)

The Battle of Vilnius, battle of Wilno, or battle of Vilna was an attack by Russian and Cossack forces of Vilnius (Wilno), the capital of the Grand Duchy of Lithuania within the Polish-Lithuanian Commonwealth, that occurred between the 7th and 9th August 1655 (sources vary: Davies states 28 July, Frost 8 August, Black 9 August ), during the Russo-Polish War (1654–1667). The Polish-Lithuanian forces under the leadership of hetman Janusz Radziwiłł were defeated by the Russian army of Alexis of Russia.

It was the first time that a foreign power managed to capture the Vilnius Castle Complex. Invading forces plundered the city for several days, and a fire consumed part of the city; in particular the Jewish quarter was burned by the Cossacks and many Jews were killed. Davies gives an estimate of 20,000 inhabitants killed in "an indiscriminate slaughter". Some scholars have suggested that certain relics, as well as the body of Vytautas the Great, were lost during the plundering of Vilnius Cathedral. The six year Muscovite occupation that followed resulted in a major depopulation and a decline of the town for many years to come.

Defeat at the battle of Vilnius was one of the reasons Janusz Radziwiłł and several other Lithuanian magnates surrendered the Grand Duchy to Sweden at the Union of Kėdainiai.