The Battle of Salis took place during the Polish–Swedish War (1600–1611) during the night of March 23–24, 1609. After the capture of Pärnu, Jan Karol Chodkiewicz, commander of the Lithuanian army, moved towards Riga, which was besieged by the Swedes under the command of Joachim Frederick von Mansfeld. Along the way, Chodkiewicz saw a chance to destroy the Swedish squadron based in the Salis port which blocked Riga. The dominant presence of the Swedes in the Baltic region gave the Lithuanian army the upper hand, as von Mansfeld and the Swedish army did not expect the possibility of an attack in such a heavily Swedish-occupied region.