The importance of the town diminished in the early 17th century, after the capital of the Commonwealth was moved from Kraków to Warsaw. In 1606, during the Zebrzydowski Rebellion, Korczyn was ransacked by the rebels, and in 1607, almost whole town with its 266 houses burned in a fire. Further and complete destruction came during the Swedish invasion of Poland, when in 1657 the town was burned to the ground, together with its extensive archives. In 1702, during the Great Northern War, Swedish troops destroyed Korczyn once again, and the town never recovered since then. After the Partitions of Poland, Nowy Korczyn briefly belonged to the Austrian Empire, and since 1815, it became part of Russian-controlled Congress Poland. Nowy Korczyn burned in 1811, 1855 and 1857, the town was also frequently flooded both by the Vistula and the Nida. In 1860, Nowy Korczyn had the population of 3,319, including 2,370 Jews. In 1869 Russian authorities stripped it of the town charter.