Nazi Germany, officially known as the German Reich and later the Greater German Reich, is a term used to describe the German state between 1933 and 1945, when Adolf Hitler and the Nazi Party controlled the country, transforming it into a totalitarian dictatorship. The Third Reich, meaning "Third Realm" or "Third Empire", referred to the Nazi claim that Nazi Germany was the successor to the earlier Holy Roman Empire (800–1806) and German Empire (1871–1918). The Third Reich, which the Nazis referred to as the Thousand-Year Reich, ended in May 1945, after only 12 years, when the Allies defeated Germany and entered the capital, Berlin, ending World War II in Europe.

Adolf Hitler was an Austrian-born German politician who was the dictator of Nazi Germany from 1933 until his suicide in 1945. He rose to power as the leader of the Nazi Party, becoming the chancellor in 1933 and then taking the title of Führer und Reichskanzler in 1934. During his dictatorship, he initiated the European theatre of World War II by invading Poland on 1 September 1939. He was closely involved in military operations throughout the war and was central to the perpetration of the Holocaust: the genocide of about six million Jews and millions of other victims.