The Poles attempted to divert the Swedes from Gdańsk by deploying an army to fight at Gniew. The fighting continued for several days until 1 October, when Sigismund ordered the withdrawal of his troops, and called on reinforcements from around the country. The battle, despite a tactical victory for Sweden, was a strategic blow to Gustavus, who was subsequently unable to besiege Gdańsk. At Dirschau, in the summer of 1627, Gustavus Adolphus was seriously wounded and the Prussian campaign came to a halt. The wound forced the king to stay in bed until autumn, and his right arm was weakened with some fingers partially paralyzed. As the major trade ports on the coast of the Baltic Sea were blocked by Swedish vessels, Sigismund sent a small squadron of ten ships under Arend Dickmann to engage the Swedes at the Battle of Oliva. It was the largest naval battle fought by the Polish royal navy, which successfully defeated the enemy fleet and broke the Swedish blockade.