During the Polish–Teutonic War of 1519–21, Morąg was again captured by Poland in 1520, after the local commander, Czech mercenary Wurgel Drahnicky, who wanted to defend the castle, was forced to submit to the Poles by the townspeople and his own troops. Upon the Protestant Reformation and the secularisation of the Order's State in 1525 it became part of Ducal Prussia, remaining a Polish fief until 1657. The estates were held by Colonel Peter von Dohna (1483–1553), Lord of Schlobitten, whose son Achatius von Dohna (1533–1619) had a castle erected. Peter's grandson Christopher von Dohna (1583–1637) became known as a scholar and governor of the Principality of Orange during the Thirty Years' War. Rebuilt in a Baroque style in the early 18th century, Dohna Castle is today used as a museum.