Meanwhile, Charles X Gustav pressed on towards Kraków, which the Swedes captured after a two months' siege. The fall of Kraków followed a capitulation of the Polish Royal armies, but before the end of the year a reaction began in Poland herself. On 18 November 1655 the Swedes invested the fortress-monastery of Częstochowa, but the Poles defended it and after a seventy days’ siege the Swedish besiegers had to retire with great loss. This success elicited popular enthusiasm in Poland and gave rise to a nationalistic and religious rhetoric concerning the war and Charles X. He was depicted as tactless and his mercenaries barbaric. His refusal to legalize his position by summoning the Polish diet and his negotiations for the partition of the very state he affected to befriend, awoke a nationalistic spirit in the country.