Today, Czersk is a small Mazovian town on the Vistula River. However, its role in Polish history was crucial. In the 11th century it was a castle protecting the Vistula ford, in the 12th century the headquarters of the castellan (regional government authority) was located here and then it became the residence of Mazovian princes. The development of Czersk was hampered by moving the capital of the princedom to Warsaw in 1406. Residing Queen Bona in Czersk in the mid-16th century led to revival of the town, but its flourishment ceased during wars with Sweden. In 1656 Czersk was burnt and the castle mined. Monumental towers, a dominant element in the Mazovian landscape, still soar on the Vistula escarpment.