The castle is a classic example of a medieval fortress and, on its completion in 1406, was the world's largest brick castle. UNESCO designated the "Castle of the Teutonic Order in Malbork" and the Malbork Castle Museum a World Heritage Site in December 1997.In 1466 both castle and town became part of Royal Prussia, a province of Poland. It served as one of the several Polish royal residences, During the Thirty Years' War, in 1626 and 1629 Swedish forces occupied the castle In 1772, the town became part of the Kingdom of Prussia province of West Prussia. At that time, the officials used the rather neglected castle as a poorhouse and barracks for the Prussian Army.With the rise of Adolf Hitler to power in the early 1930s, the Nazis used the castle as a destination for annual pilgrimages of both the Hitler Youth and the League of German Girls. The Teutonic Castle at Marienburg served as a blueprint for the Order Castles of the Third Reich built under Hitler's reign. In 1945 during World War II combat in the area, more than half the castle was destroyed.