On 21 April 1703 Stenbock participated, along with Charles XII, in the Battle of Pułtusk against the Saxon Field Marshal Adam Heinrich von Steinau. On May of that year, Charles XII laid siege to Thorn on the Weichsel river. Since he lacked siege artillery, Charles XII ordered cannons and equipment from Riga and Stockholm, which had to pass through Danzig at the mouth of the Weichsel. Stenbock was sent incognito to Danzig to negotiate with the city's magistrate about a free passage for the Swedish transport vessels. At the end of July the transport fleet from Riga arrived at Danzig with 4,000 Swedish and Finnish recruits. Even though Stenbock was granted a contribution of 100,000 riksdaler, the city refused to open its harbor barriers for the Swedish vessels and Stenbock was forced to transport the siege artillery by land. He arrived at the Swedish field camp at Thorn with the artillery at the end of August. The city was bombarded during the autumn and, on 3 October, the city's garrison surrendered to Charles XII. In December a new conflict with Danzig was triggered by Stenbock attempting to recruit troops around the area, even though freedom from enlistment was one of Danzig's privileges. However, Charles XII demanded that recruitment must be allowed, and the city submitted to his demands in January 1704. Subsequently, however, the King further demanded a refund of 15,000 silver marks which the exiled Charles VIII of Sweden offered to the city nearly 250 years earlier in return for fishing revenue from Putzig. Members of the Gyllenstierna family had already presented the demands as heirs to Charles VIII the previous year, and Stenbock and the King returned to Danzig to press Gyllenstierna's demands. Eventually the city relented and paid 136,000 riksdaler in exchange for a letter of safe conduct from Charles XII.