At the beginning of June 1627, King Gustavus Adolphus was lightly wounded while attempting a night-crossing of the River Vistula in a boat near (Kieżmark), south of Danzig (Gdańsk), and had to retreat. In July he led a force to lift the siege of Braniewo, and lay siege to Orneta (Wormditt). Hetman Koniecpolski responded with the sudden attack and capture of Gniew. Gustavus Adolphus was reported to have been impressed by the speed of Koniecpolski's reaction. Later at the Battle of Dirschau (modern Tczew), Koniecpolski with about 7,800 men (including 2,500 cavalry and hussars), tried to stop the Swedish army (10,000 men including 5,000 infantry) from reaching Danzig. A major battle was fought between 17 and 18 August 1627 (in the new style calendar), with the Swedish forces positioned near the marshes of the River Motława. The Swedes hoped to provoke the Poles into a reckless attack and then to destroy them with infantry fire and artillery, but Koniecpolski decided otherwise. The Swedes then took the initiative and attacked with cavalry, and managed to deal severe damage to the Polish cavalry, but failed to inflict a crippling blow on the main body of the army (the morale of which remained high, mostly thanks to Koniecpolski). When, King Gustavus Adolphus was shot in the shoulder by a Polish sniper, the Swedes decided to end the assault and withdrew from the field, reportedly in good order.