The Order of the Knights of the Hospital of St Mary of the Teutons in Jerusalem commonly known as the Teutonic Knights or the Teutonic Order was founded by German pilgrims from Lubeck and Bremen during the Siege of Acre in 1190 and recognized by Pope Celestine III in 1192. The Teutonic Knights followed the examples of both Knights Hospitaller and Knights Templar: they adopted the hospital work after the Knights Hospitaller and military organization after the Knights Templar.
In contrary to the Knights Hospitaller and Knights Templar activities of which were primarily tied to the Holy Land, the Teutonic Knights focused on Crusades in Europe already in the early 13th century. The Teutonic Knights under Grand Master Hermann von Salza (1210-1239) accepted the invitation of Andrew II of Hungary to protect the eastern borders of his kingdom against the pagan Cumans and settled in Transylvania in 1211. They fought successfully against the Cumans and established the city of Brasov but their great influence in the region started to disturb Andrew II who forced the Teutonic Knights to leave Transylvania in 1225.
About the same time they were asked for military assistance against the pagan Prussians by the Polish Duke Conrad of Mazovia. Conrad promised them the Chelmno Land, while Holy Roman Emperor Frederick II granted the Teutonic Knights the lands promised by Conrad as well all the lands they could capture from the Prussians with the so-called Golden Bull of Rimini in 1226. The Teutonic Knights also secured privileges from Pope Gregory IX who decreed that all current and future conquests of the Teutonic Knights were the property of the Holy See held in perpetuity by the Teutonic Knights.
Frederick’s Golden Bull of Rimini and Pope Gregory’s decree provided the legal basis for the establishment of the Monastic state of the Teutonic Knights. The order started with conquest of Prussia in 1233 and over the following five decades subdued the entire region, later known as the East Prussia and West Prussia. In 1237, the Teutonic Knights absorbed the Livonian Brothers of the Sword, a military order founded in 1202 to Christianize the pagan Livonians. The organization of the Teutonic Knights was strongly centralized although they granted considerable freedom to the cities many of which joined the Hanseatic League, an alliance of trade cities which had a trade monopoly from the Baltic to the North Sea.
After the Teutonic Knights established themselves in Livonia they started to invade the Russian lands. However, their military campaigns in Russia were abandoned after the order was decisively defeated by Alexander Nevsky on the ice of the Lake Peipus in 1242. Afterwards the Teutonic Knights concentrated on warfare against Lithuania and Poland capturing Pomerelia and city of Gdansk (Danzig) in 1308/1309.
The territorial expansion of the Teutonic Knights resulted in massive German colonization of the Prussian lands as well as in incessant warfare with Poland and Lithuania which eventually joined their forces against the order. The Polish-Lithuanian forces severely defeated the Teutonic Knights at the Battle of Grunwald (Tannenberg) in 1410. The Teutonic Knights never recovered from the defeat at Tannenberg but Poland and Lithuania had to launch several military campaigns to destroy the order. The Teutonic Knights were forced to cede West Prussia and Pomerelia to Poland, while the East Prussia was made a Polish fief with the second Treaty of Torun in 1466.
The rule of the Teutonic Knights in Prussia finally collapsed in 1525 when Grand Master Albert of Brandenburg accepted Protestantism, dissolved the order and declared Prussia a secular duchy under Polish suzerainty. The Teutonic Knights retained several holdings in the Holy Roman Empire and Livonia but the order lost its former prestige and influence. They lost all their holdings with exception of small territories in the Habsburg Monarchy by 1809.
Austrian Emperor Francis I revived the order under supreme authority of the Austrian Emperor, while the dignity of grand master was reserved for archduke of the Habsburg House until the last Habsburg Grand Master, Archduke Eugen resigned in 1923. The order received a new Rule with Papal sanction on November 27, 1929, which reconstituted it as purely religious order. Today, the headquarters of the order are in Vienna, while branch houses also exists in Bavaria, Hesse and the Italian Tyrol.