Teutonic knights' heritage is mixed - both negative and positive. In the eyes of Poles Teutonic knights were seen negatively. Teutonic knights were cruel fighters dressed in white coats with black crosses and they were the symbols of war and destruction. The Teutonic knights basically eradicated old Prussians - the Baltic people under the pretext of converting them to Christianity. The name Prussia was not forgotten since it was accepted as a name of the XIX century Prussian empire.
Teutonic knights brought not only the disaster but also the technological progress. They build the network of 120 castles during 200 years of their rein. The castles are situated one from the other not further than 30 km away - one day of the horse ride, since the strict Teutonic rule did not allow Teutonic travelers to spent the night outside of the castle. The tight network of castles also simplified the communication between the knights in different castles. The knights could send light signals between the castles in the case of danger. Building so many castles is quite an achievement of these medieval times, more than one new castle during 2 years. It is also the reflection of the order power and engineering art. Their biggest castle - Malbork (Marienburg, the castle devoted to St.Mary) is the biggest brick castle in the world!
Eyewitness Travel Guide to Poland by Teresa Czerniewics-Umer, Malgorzata Omilanowska, Jerzy S. Majewski, DK Travel Writers