In 1623, while near Gdańsk (Danzig), he witnessed the arrogant attitude of Gustavus Adolphus, whose navy took opportunity of its sea superiority to demand concessions from Gdańsk (the Commonwealth had no navy). In 1624 king Sigismund decided that the time had come for Władysław to travel, like many of his peers, to Western Europe. For security reasons, Władysław traveled under a fake name, Snopkowski (from Polish Snopek, meaning , as seen in the Vasa's coat of arms). In his voyage (1624–1625) he was accompanied by Albrycht Stanisław Radziwiłł and other, less notable courtiers. First, he travelled to Wrocław (Breslau), then Munich, where he met Maximilian I, Elector of Bavaria. In Brussels he met Infanta Isabella Clara Eugenia of Spain; in Antwerp, Rubens. Near Breda he met Ambrosio Spinola. It was during his stay with Spinola that he was impressed by Western military techniques; this was later reflected when he became king, as military matters were always important to him. While not a military genius, and surpassed by his contemporary, Commonwealth hetman Stanisław Koniecpolski, Władysław was known as a fairly skillful commander on his own. In Rome he was welcomed by Pope Urban VIII, who congratulated him on his fighting against the Ottomans. During his stay in Florence he was impressed by opera, and decided to bring this form of art to the Commonwealth, where it was previously unknown. In Genoa and Venice he was impressed by the local shipyards, and in Pisa he witnessed a specially organized mock naval battle, experiences that resulted in his later attempt to create the Polish–Lithuanian Commonwealth Navy.