The war between Pomerania and the Teutonic Knights is renewed in 1247 when large Teutonic reinforcements arrive in Prussia.

On Christmas Eve of 1247, the Knights besieged and overwhelm a major Pogesanian fortress, which they later rename Christburg (Dzierzgoń), and newly arrived Henry III, Margrave of Meissen, subdues the Pogesanians.

Swietopolk retaliates and destroys Christburg, but the Knights rebuild it in a new location.

Both the Prussian and Pomeranian armies fail to capture the new castle.

The Prussians are compelled to sign the Treaty of Christburg on February 7, 1249.

The treaty provides personal freedom and rights to newly converted Christians.