In the year 1627 a fire destroyed parts of the town. During the Second Northern War (against Sweden, 1655–1660) the Battle of Chojnice (1656) was fought. The town suffered heavily from the siege, plundering and fire, especially in 1657. Cloth production declined as a result of the Swedish invasion, however, it soon revived. In 1733–1744 the Baroque Jesuit Church of the Annunciation of the Blessed Virgin Mary was built. A large fire destroyed the town again in 1742.