When the mission of the order in Palestine was nearing its end, the Teutonic Knights moved their headquarter to Venice. The only way to continue their mission seemed to involve moving their theatre of operations to Eastern Europe, on the border with pagan nations. The Knights offered their services to the local Christian rulers posing as religiously motivated mercenaries. Nevertheless, they hoped that using their influence in the Holy Roman Empire could help them become territorial proprietors of the newly conquered lands.
In 1211 Andrew II of Hungary accepted their services. They were granted the district of Burzenland[?] in Transylvania. Andrew had been involved in negotiations for the marriage of his daughter with the son of Hermann, the Landgrave of Thuringia. The latter's vassals included the family of Hermann of Salza[?], the new master of the Teutonic Order. Led by a brother called Theoderich, they defended the Kingdom of Hungary from the neighbouring Cumans[?]. In 1224 they petitioned Pope Honorius III to be placed directly under the authority of the papal see, rather than the Kingdom of Hungary. King Andrew responded by expelling them in 1225
At the same time Konrad I Mazowiecki[?], ruler of part of Poland, suffered when pagan Old Prussians[?] occupied Culmerland[?]. In order to restore this province and conquer Prussia, Konrad hired the Knights, giving them Culmerland[?] as a fief (1226). However, in 1234 the Order received privileges from the emperor that made them independent rulers of Culmerland and Prussia. The rulers of Poland resented this, as they perceived those provinces as part of Poland.
Thanks to the income from the land owned by the Order in Western Europe, and its lack of scruples, the war of attrition against th Old Prussians had already been finished when the Teutonic Order conquered or slaughtered all theOld Prussians.
They ruled over much of the Baltic for several centuries, losing power finally in the 1466. In addition they founded numerous cities all over Central and Eastern Europe.
The Order began to lose influence during the late Middle Ages, as the Commonwealth of Poland-Lithuania[?] was founded. Soon the Order was involved in many wars against Poland, Lithuania and the Tatars. The biggest battle of the Teutonic Knights was the Battle of Tannenberg (1410) (in Polish, Battle of Grunwald), which they lost.
Later, the burghers of Prussia rose up against the Catholic Teutonic order and their power waned further. The emperor Maximilian I had made an agreement with the Polish king and in 1525, the grand master of the order, Albrecht of Brandenburg, converted to Lutheranism and swore allegiance to the Polish king, who made him the Duke of Prussia. This Polish king was also the grand duke of Lithuania, Sigismund I, and was Albrecht of Brandenburg's uncle.
The new Grand Magistery was then established in Württemberg and members of the Habsburg family continued as grand masters over the Order's considerable holdings in Germany until 1809, when the Order lost its last secular holdings. The order continued to exist, headed by Habsburgs through the First World War, and today operates primarily as a charitable organization.