Władysław Eugeniusz Sikorski (20th May 1881 - 4th July 4, 1943) was a Polish military and political leader. Prior to World War I, he established and participated in several underground organizations that promoted the cause of Polish independence. He fought with distinction in the Polish Legions during World War I, and later in the newly created Polish Army during the Polish-Soviet War (1919 to 1921). In that war he played a prominent role in the decisive Battle of Warsaw.