Hussite invasion of PrussiaOliwa, Gdańsk, Poland
In June 1433 Poland allied itself with the Czech Hussites in order to stop the Teutonic Order from sending secret support to Švitrigaila via its Livonian branch. The Teutonic Knights had supported the Pope and Holy Roman Emperor Sigismund against the heretic Hussites during the Hussite Wars. Czech forces under Jan Čapek of Sány were granted safe passage through Poland for their last and largest "beautiful ride." The Polish forces were also supported by Pomeranian Duke Bogusław IX of the Duchy of Stolp (Słupsk). In addition, the Moldavians, whose ruler Iliaş had been replaced by the more pro-Polish Stephen II, had joined the Polish alliance. For four months the Hussite army, including forces led by Feodor Ostrogski, ravaged Teutonic territories in Neumark, Pomerania, and western Prussia. First they unsuccessfully besieged Konitz (Chojnice) for six weeks, then moved north to Schwetz (Świecie) and Danzig (Gdańsk). They captured several towns and castles, including Dirschau (Tczew) on the Vistula River (29 August 1433). Despite their failed siege of Danzig, the Hussites reached the Baltic Sea near Oliwa at the beginning of September and celebrated their "beautiful ride" by symbolically filing their bottles with water from the sea. Returning to the south via Starogard Gdański, the expedition occupied a castle in the frontier settlement of Nowy Jasiniec.