In addition to its original merchant functions the Main Square witnessed many historical events, and it was used to stage public executions of prisoners held in the city's Town Hall. It was a place of regal ceremonies as part of the Royal Road ("Droga Królewska"), frequented by diplomats and dignitaries traveling to Wawel Castle. In 1364 King Casimir held the Pan-European Congress of Kraków there. On 10 April 1525, Albert I, Duke of Prussia paid the Prussian Homage to Sigismund I the Old, king of Poland and Grand Duke of Lithuania, accepting Polish kings' suzerainty, ("pictured"). In 1514 Lithuanian duke Konstanty Ostrogski held a victory parade over the Muscovy and in 1531 nobleman Jan Tarnowski celebrated another victory in the Muscovite wars. Jan III Sobieski, a King of Poland and Grand Duke of Lithuania, celebrated there his victory over the Turkish Empire in the 1683 Battle of Vienna.