The Deluge was a series of mid-17th-century military campaigns in the Polish–Lithuanian Commonwealth. In a stricter sense, the term refers to the Swedish invasion and occupation of the Commonwealth as a theatre of the Second Northern War (1655–1660) only; in Poland and Lithuania this period is called the Swedish Deluge (Polish: potop szwedzki, Lithuanian: švedų tvanas, Swedish: svenska syndafloden), or less commonly the Russo–Swedish Deluge (Polish: Potop szwedzko-rosyjski) due to the simultaneous Russo-Polish War. In a wider sense, it applies to the period between the Khmelnytsky Uprising of 1648 and the Truce of Andrusovo in 1667, comprising the Polish theatres of the Russo-Polish and Second Northern Wars. The term "deluge" (potop in Polish) was popularized by Henryk Sienkiewicz in his novel The Deluge (1886).
During the wars the Commonwealth lost approximately one third of its population as well as its status as a great power due to invasions by Sweden and Russia. According to Professor Andrzej Rottermund, manager of the Royal Castle in Warsaw, the destruction of Poland in the Deluge was more extensive than the destruction of the country in World War II. Rottermund claims that Swedish invaders robbed the Commonwealth of its most important riches, and most of the stolen items never returned to Poland. Warsaw, the capital of the Polish–Lithuanian Commonwealth, was destroyed by the Swedes, and out of a pre-war population of 20,000, only 2,000 remained in the city after the war. According to the 2012 Polish estimates, the material damage caused by the Swedish army amounted to 4 billion złotys. 188 cities and towns, 186 villages, 136 churches, 89 palaces, and 81 castles were completely destroyed in Poland.
