Foreign courts did not avail themselves of the opportunity to promote their own candidates for the Polish throne. Austria's Habsburgs were well disposed toward the Polish Vasas and did not put forward a contender. Fears that King Gustavus II Adolphus, of the Swedish Vasas, would put forward his own candidacy proved unfounded, though his envoy Steno Belke did argue that Władysław should renounce his claim to the Swedish throne (Władysław declined.) Foreign envoys such as Papal Nuncio Honorat Visconti and the Holy Roman Emperor's envoy Count Julius Mosberg declared their support for Władysław. The Duke of Prussia, George William, Elector of Brandenburg, asked to be permitted to participate in the election sejm but this request was turned down. Muscovy was just then preparing for war with the Commonwealth and failed to put forward a candidate—indeed, it attacked while the election sejm was subsequently in session.