On 24 March 1702 Carl Piper, head of the Field Chancery, held a couple of important meetings in Jurburg (Jurbarkas) on the right bank of the river Neman. He first held talks with Mikołaj Franciszek Ogiński, Court Treasurer of Lithuania. Oginski claimed that he had been sent by Prince Jakub Ludwik Sobieski with an important mission. Oginski wanted the Swedish forces to continue advancing towards Warsaw in order to force King Augustus to flee. The whole army would not be needed, Oginski suggested. 3,000-4,000 would be entirely sufficient. It would also be advisable to have some units march on Vilnius. The most important part of his mission from Prince Jakub did however concern the Cossacks and Tatars. They would be able to give Sweden assistance in the war with Russia. Oginski possessed, he claimed, estates near the border to the Cossacks and they had told him of their fear of Russia and how the Czar already had begun to limit their rights. The Cossacks had informed both Cardinal Radziejowski and Prince Jakub of their need for foreign support and they had thought it best to contact Charles XII.
Piper replied that it seemed risky to make contact with the Cossacks, who had "neither head nor firm decisions" - Mazepa had been arrested by the Czar and had no deputy. Oginski said that the arrest of Mazepa had caused a lot of irritation among the Cossacks, but there were 15 colonels who corresponded with each other about the important decisions.
Help could also be obtained from the Tatars if they received money. But, the Swedes replied, the Tatars were allied with the Ottoman Empire. Could they really go to war wíth Russia without his permission? Oginski did not give a clear reply to this, but said that the Ottomans were less than happy with the Russians and the Tatars feared that the Czar had designs on their land.
Piper promised that he would bring the matter to the King's attention and praised Oginski's devotion. Oginski assured Piper that he had taken no part in his brother's rebellion - they had always been in disagreement. The Court Treasurer said that he would send a message through his son in Vilnius and recommend Grzegorz Antoni to make peace with the Sapiehas.
Source: Riksarkivet, Diplomatica, Polonica, vol. 310.