Poland during the Jagiellonian dynasty
Polish–Teutonic WarNakło nad Notecią, Poland
The war broke out after Teutonic Grand Master Paul von Rusdorf signed the Treaty of Christmemel, creating an alliance with Švitrigaila, who was waging a civil war against his brother Polish King Jogaila (Władysław Jagiełło) for the throne of the Grand Duchy of Lithuania. Sigismund of Luxemburg made a commitment to the Teutonic Order in an effort to break the Polish–Lithuanian union.
In 1431, while the main Polish forces were involved in Lutsk in Volhynia, the Teutonic Knights invaded Poland. Finding little opposition, the Knights ravaged Dobrzyń Land, taking the town of Nieszawa, and tried to move on to the Kuyavia and Krajna regions. However, the Teutonic army was defeated on 13 September 1431 in the Battle of Dąbki, near Nakel (Nakło nad Notecią). In September a two-year truce was signed among Poland, Lithuania and the Teutonic Knights at Staryi Chortoryisk.