Przemysł II, King of Poland since 1295, incorporated Pomerelia (Pomorze Gdańskie) into the Lands of the Polish Crown, against the protest of the Imperial Margraviate of Brandenburg referring to the Treaty of Arnswalde signed with Duke Mestwin in 1269.

On the other hand, the Kingdom of Bohemia, since 1310 under the rule of the mighty House of Luxembourg, rose again, and King John the Blind himself claimed the Polish crown as a heritage from the Přemyslids.

Taking advantage of the weakness of Poland due to the internal fragmentation, the Teutonic knights pillaged and conquered the Polish Kuyavian region and the Dobrzyń Land.

King Władysław received help from Lithuania and Hungary – commanded by William Drugeth – and in turn pillaged the Kulmerland of Teutonic Prussia up to the Osa River near Grudziądz.

A Polish and Lithuanian counterattack in 1330 resulted in a temporary peace, with the Order returning part of its military gains to Poland, but over the next year, the fighting continued.

In 1343, the territorial claims of the parties were settled in the Peace of Kalisz signed by Władysław's son King Casimir III, formally ending the war.