Józef Klemens Piłsudski[a] was a Polish statesman who served as the Chief of State (1918–1922) and first Marshal of Poland (from 1920). In the aftermath of World War I, he became an increasingly dominant figure in Polish politics and exerted significant influence on shaping the country's foreign policy. Piłsudski is viewed as a father of the Second Polish Republic, which was re-established in 1918, 123 years after the final partition of Poland in 1795, and was considered de facto leader (1926–1935) of the Second Republic as the Minister of Military Affairs.
Seeing himself as a descendant of the culture and traditions of the Polish–Lithuanian Commonwealth, Piłsudski believed in a multi-ethnic Poland—"a home of nations" including indigenous ethnic and religious minorities to be assimilated as Poles. Early in his political career, Piłsudski became a leader of the Polish Socialist Party. Believing Poland's independence would be won militarily, he formed the Polish Legions. In 1914, he predicted a new major war would defeat the Russian Empire and the Central Powers. After World War I began in 1914, Piłsudski's Legions fought alongside Austria-Hungary against Russia.