In 1601 Żółkiewski operated in the north, in Livonia (Inflanty), during the Polish–Swedish War. He also took part in the successful siege of Wolmar, and in 1602 the taking of Fellin. That same year he led Polish forces at the battle of Reval, which led to a Swedish capitulation at the siege of Biały Kamień. Żólkiewski became ill near the end of the campaign and had to relinquish command of his forces to Hetman Jan Karol Chodkiewicz.