In the autumn of 1620, Özi Beylerbeyi İskender Pasha seized the secret letter sent by Transylvanian Prince Bethlen Gabor to Istanbul and sent it to Poland, and Osman also became a veteran of the people around him. He decided to embark on a Polish expedition. Continuing preparations for the Polish campaign, neither cold nor famine nor the British ambassador John Eyre could deter Osman. The ambassador of Sigismund, the King of Poland, was brought into Istanbul despite the severe colds. The janissaries and army were not willing to go on a campaign, regardless of their conditions.