Despite the Swedes' strong defense, their commander Olof Andersson Stråle ultimately surrendered to the Danes' larger fighting forces.

Therefore, it was important for Christian IV to control the city in order to block Sweden from getting cargo from the north sea, and possibly connecting Denmark and Norway by land in the future.

On May 5, a portion of the Danish army group under the command of Christian IV reached the city and put Älvsborg under siege.

The rest of the army arrived on 14th of May, but two days before, in the night between the 11th and 12th, Christian IV begun shooting on the Castle and digging closer to the city.

The Swedes, determined to defend the castle, manged the hold off the Danish army by exploding the entrance, inflicting many casualties.

The damage done by the Danes had caused a lot of Swedish casualties, however when Christian IV on the 23rd asked the Swedes for the surrender of the castle again they refused, saying they would take a day to think it over.