Adolf Hitler became the leader of a political party in 1921.
Adolf Hitler ( [ ˈadɔlf ˈhɪtlɐ ] ; 20 April 1889 -- 30 April 1945 ) was a German politician who was the leader of the Nazi Party ( Nationalsozialistische Deutsche Arbeiterpartei ; NSDAP ) , Chancellor of Germany from 1933 to 1945 , and Führer ( `` Leader '' ) of Nazi Germany from 1934 to 1945 . He joined the German Workers ' Party ( DAP ) , the precursor of the NSDAP , in 1919 and became leader of the NSDAP in 1921 .