In the early 17th century, Dukla emerged as an important center of commerce, located on a trade route joining Poland with Hungary. The town had a defensive wall with two towers, and a town hall. Its merchants traded Hungarian wine, which at that time was very popular among Polish nobility. In 1638, Franciszek Mniszech began construction of a new palace, which was completed by his son Jan Mniszech. On January 2, 1656, during the Swedish invasion of Poland, King John II Casimir came to Dukla, on his way from Silesia back to the occupied country. One year later, on March 16, 1657, Dukla was destroyed and looted by Transilvanian army of George II Rakoczi. After the wars, the town declined. Furthermore, Dukla was again destroyed in the Great Northern War, and its wooden houses burned in 1724, 1725, 1738, and 1758.