The treaty concluded the Thirteen Years' War which had begun in February 1454 with the revolt of the Prussian Confederation, led by the cities of Danzig, Elbing, Kulm and Thorn, and the Prussian gentry against the rule of the Teutonic Knights in the Monastic State, in order to join the Kingdom of Poland. Both sides agreed to seek confirmation from Pope Paul II and Holy Roman Emperor Frederick III, but the Polish side stressed that this confirmation would not be needed for validation of the treaty. The peace talks were held in Nieszawa from September 23, 1466, and in the final stages moved to Toruń.
Terms
In the treaty, the Teutonic Order renounced any claims to the territories of Gdańsk/Eastern Pomerania and Chełmno Land, which were reintegrated with Poland,, and the region of Elbing and Marienburg, and the Bishopric of Warmia, which were also recognized as part of Poland. The eastern part remained with the Teutonic Order as a fief and protectorate of Poland, also considered an integral part of "one and indivisible" Kingdom of Poland. The Roman Catholic Diocese of Chełmno became a suffragan of the Archdiocese of Gniezno. From now on, every Grand Master of the Teutonic Order was obliged to swear an oath of allegiance to the reigning Polish king within six months of taking office, and any new territorial acquisitions by the Teutonic Order, also outside Prussia, would also be incorporated into Poland. The Grand Master became a prince and counselor of the Polish king and the Kingdom of Poland. Poles were to be admitted to the Teutonic Order. The Teutonic Knights were obliged to help Poland in the event of war, and were forbidden to wage war against Catholics without the consent of Polish kings. Any prisoners of war on both sides were to be released. The treaty also dismissed any possibility of releasing the Teutonic Order from dependence to Poland or of any revision of the terms of the treaty by referring to any foreign authority, including imperial and papal.
Outcome
The territories directly held by Poland were already organized into three voivodeships and the Prince-Bishopric of Warmia, all of which formed the province of Royal Prussia, which was considered the exclusive property of the Polish king and Polish kingdom. Later some disagreements arose concerning certain prerogatives that Royal Prussia and the cities held, like Danzig's privileges. The region possessed certain privileges such as the minting of its own coins, its own Diet meetings, its own military, and its own administrative usage of the German language. A conflict over the right to name and approve Bishops in Warmia, resulted in the War of the Priests. Eventually, Royal Prussia became integrated into the Polish–Lithuanian Commonwealth, but retained some distinctive features until the partitions of Poland in the late 18th century. In 1525, the Order was ousted from their territory by its own Grand Master when Albert, Duke of Prussia adopted Lutheranism and assumed the title of duke as hereditary ruler under the overlordship of Poland in the Prussian Homage. The area became known as the Duchy of Prussia.
