The Teutonic Knights tried to regain the fortress (Ordensburg) of Malbork (or Marienburg), which had been the capital of their state, but was captured by the Kingdom of Poland in June 1457.

In the spring of 1457, the garrison of Marienburg, composed of mercenaries (mostly from Bohemia), hired by the Teutonic Knights, began negotiations with Polish King Casimir IV Jagiellon.

In the Battle of Sępopole, the Polish pospolite ruszenie was defeated, and main Teutonic forces, commanded by Moravian mercenary, Bernard Szumborski, headed towards Marienburg.

Marienburg was defended by Jan Koscielecki and Prandota Lubieszowski, while Polish King was unable to gather an army, due to never-ending arguments with the magnates.

The negotiations strengthened the position of the Knights, as they were supported by Bohemian ruler George of Podebrady, who feared that Casimir IV Jagiellon would try to grab his throne.