With the advent of the first news of the pretender to the Moscow throne announced in Poland and his support by the Poles, Charles IX began to pay more attention to the situation in the east. On the one hand, Sweden fought with Poland and it was impossible to allow its strengthening due to Russian lands or its rapprochement with Russia. On the other hand, a peace treaty was recently signed with Russia, according to which Sweden had to return most of Ingermanland. Having decided to use the difficult situation of the Moscow government and at the same time to tie the forces of the Commonwealth, the king at the beginning of 1604 offered a large army to help Boris Godunov. And in February 1605, an embassy went from Stockholm to Moscow to conclude an agreement. The price of military support was supposed to be the transfer of Sweden to the cities of Ivangorod, Yam, Koporye and Korela. Due to the sudden death of Boris Godunov, negotiations did not take place, and False Dmitry I soon ascended the throne.