Second Treaty of Thorn

The Second Treaty of Thorn (October 19, 1466) ended the Thirteen Years War or "War of the Cities", which had begun with the revolt (February 1454) of the Prussian Confederation led by the cities of Gdansk, Elblag and Torun (then Danzig, Elbing and Thorn, respectively) against the rule of the Teutonic Knights.

The Treaty partitioned the defeated Teutonic Order's territory in the land then known as Prussia. The Order surrendered to the Polish crown (which had supported the Confederation) its rights over Prussia's western half (subsequently known as Polish or Royal Prussia).

The Order retained control of eastern Prussia under the overlordship of the Polish king, but lost this territory also in 1525, when its Grand Master Albert of Brandenburg adopted Lutheranism and assumed the title of Duke as hereditary ruler, the area subsequently being known as Ducal Prussia.