Teutonic knights were originally created in 1190 during the third Crusade to take care of the German pilgrims in the Holy Land. In the beginning of the XI century the order changed from being a hospice brotherhood to primarily military order. The head of the order became known as the Grand Master (Hochmeister). In 1211 a Hungarian king accepted their service in Transylvania but when Teutonian knights petitioned the pope to be placed directly under papal rule than the rule of the King of Hungary - they were expelled from Hungary (1225).
In 1226 the Konrad I of Mazovia invited the kings to the west-central Poland to help to defend Polish boarders from Pagan Prussians. Unfortunately, he did not realize that letting Teutonic knights to settle in Poland would bring more problems than sporadic fights with the pagan Prussians. Teutonic knights not only destroyed Prussia's existence by killing almost the whole population and eradicating Prussia state and nation. They also subdued lots of Polish territories and were endangering also the territories and the people of neighboring nations: Estonia, Latvia and Lithuania. The danger of Teutonic growing power caused Poland and Lithuania to form a union under one king. mainly for a protection of their boarders from Teutonic aggression. Teutonic Knights were called in Poland Krzyzacy since they carried the black crosses on white coats.
In 1410, a Polish-Lithuanian army decisively defeated the order of Teutonic knights and broke its military power at the Battle of Grunwald (Tannenberg). In 1466, in the Peace of Torun, Teutonic knights lost western Prussia to Poland in the process. The famous Prussian Homage painted by jan Matejko shows Albert to reign the position as the Grand Master and receive a title of the "Duke of Lithuania" from Polish king Zygmunt (Sigismundus) the Old, in 1525 year. Ducal Prussia was converted into the the first protestant state in the same time when it became a vassal of the Polish Crown. The new Prussia which became a power in XVIII & XIX centuries under the reign of Frederick II of Prussia (1740-1786) and later the chancellor Otto von Bismarck revived the tradition of old Prussia under Teutonic order. Also during the Nazi times the history of Teutonic order was revived especially in the aspect of the Germanic supremacy over Eastern Europe and Slavs.
Eyewitness Travel Guide to Poland by Teresa Czerniewics-Umer, Malgorzata Omilanowska, Jerzy S. Majewski, DK Travel Writers
The Rough Guide to Poland by Mark Salter, Jonathan Bousfield