The Battle of Westerplatte was the first battle of the German invasion of Poland, marking the start of World War II in Europe. In the mid-1920s the Second Polish Republic established the Polish Military Transit Depot (Wojskowa Składnica Tranzytowa, WST) on the Westerplatte peninsula in the harbor of the Free City of Danzig. Beginning on 1 September 1939, the German Wehrmacht and Danzig Police assaulted the WST. Despite initial assessment on both sides that the Polish garrison might hold out for several hours before being reinforced or overwhelmed, the Poles held out for seven days and repelled thirteen assaults that included dive-bomber attacks and naval shelling. The defence of the Westerplatte was an inspiration for the Polish Army and people in the face of German advances elsewhere and is still regarded as a symbol of resistance in modern Poland.