Polish forces, numbering around 15,000, with 50 pieces of artillery, led by the Grand Crown Hetman Jan Zamoyski besieged the city (present-day Valmiera) defended by about 1,000 infantry under Jacob De la Gardie and Carl Carlsson Gyllenhielm.

The king of Poland, Sigismund III Vasa, was initially present at the siege, but left for Wilno on December 5.

At first the Swedish artillery managed to hold back the Poles who did not intend to storm Wolmar without proper siege cannons.

Finally on December 18, when the cannons had breached two entrances in the walls, the Polish troops managed to storm the defenses and entered the city.

The captured Swedish generals Pontus De la Gardie and Carl Carlsson Gyllenhielm were treated very well until they were transferred to the king.