Reszel was originally a settlement built by the Bartian tribe of Old Prussians and conquered by the Teutonic Knights in 1241. The native Prussians later recaptured the settlement and held it for five years, but were eventually defeated by the German crusaders. Reszel received its town privileges in 1337 under Chełmno Law. After the Polish victory in the Battle of Grunwald in 1410, the town was briefly captured by Poles led by King Władysław II Jagiełło.