Adolf Hitler was the leader of Nazi Germany during World War II. He rose to power as Chancellor in 1933 and later established a totalitarian regime under the Nazi Party. His aggressive expansionist policies led to the invasion of Poland in 1939, triggering the war. Hitler's ideology centered around ideas of Aryan supremacy, which resulted in the Holocaust, the systematic persecution and extermination of six million Jews and various other minority groups. His regime came to an end in 1945 with Nazi Germany's defeat by Allied forces.