The Deutschordensschloss, or Teutonic Order Castle, is a historical fortress located in various regions of Europe, primarily associated with the Teutonic Knights. These knights were a medieval Catholic military order founded in the late 12th century, known for their role in the Crusades and the establishment of Christian states in Eastern Europe. One of the most notable examples of a Deutschordensschloss is in Malbork, Poland, which is the largest brick castle in the world and a UNESCO World Heritage site. The castle served as the headquarters of the Teutonic Knights and showcases impressive Gothic architecture, reflecting the order's power and influence during the Middle Ages.