Duchy established 1815 Congress Poland established 1830 November Uprising 1863 January Uprising 1914 World War I begins 1918 Capital of the Second Polish Republic 1920 Battle of Warsaw 1925 Polskie Radio starts 1934 Opening of Chopin Airport 1939 World War II begins 1939 Siege of Warsaw 1943 Warsaw Ghetto Uprising 1944 Warsaw Uprising