[1] By the end of 1521 the Teutonic Knights were forced to ask for an armistice and in 1525 the Grand Master of the Order, Albrecht Hohenzollern, paid homage to the Polish king, Sigismund the Old.

In the Second Peace of Thorn, Royal Prussia became part of the Crown of the Kingdom of Poland, although with special local privileges.

As a result, in 1519 war broke out between the Teutonic Knights and the Kingdom of Poland, with the region of Warmia as a major scene of conflict.

[1] In January 1520, they besieged Frauenburg, and eventually burned the whole town, including the houses of the canons (clerical administrators of Warmia) and that of Copernicus.

[7] As a result, Copernicus was forced to move to Allenstein where he was put in charge of organizing the defense of the city against the expected attack.

He improved the fortifications and stockpiled food and supplies,[5] in the hope that the city could hold out long enough for reinforcements from the King of Poland to arrive.

Sigismund, however, learned of the threat through other channels[3] and the garrison of the town was expanded to 200 when a unit of infantry, under the leadership of the Czech commander Henryk Peryk of Janowice arrived.

[1] On January 26 the Knights launched their assault on the town, led by Wilhelm von Schaumber, near the Brama Młyńska (Mill Gate).