National Socialism, more commonly known as Nazism, is the ideology and set of practices associated with the 20th-century German Nazi Party, Nazi Germany, and other far-right groups. Sometimes characterised as a form of fascism that incorporates scientific racism and antisemitism, Nazism's development was influenced by German nationalism (especially Pan-Germanism), the Völkisch movement and the anti-communist Freikorps paramilitary groups that emerged during the Weimar Republic after Germany's defeat in First World War.
Nazi Germany and the Third Reich are common names for Germany during the period from 1933 to 1945, when its government was controlled by Adolf Hitler and his National Socialist German Workers' Party (NSDAP), commonly known as the Nazi Party. On 30 January 1933 Hitler became Chancellor of Germany. Thereafter, the Nazi Party began to quickly eliminate all political opposition and consolidate their power. The Gestapo (secret state police) and SS under Heinrich Himmler destroyed the dissenting liberal, socialist, and communist political parties, and oversaw the persecution and mass murder of Jews throughout Nazi-occupied territories. The other Nazi paramilitary organization was the SA. The state idolized Hitler as its Führer ("leader"). Germany was transformed into a totalitarian state where nearly all aspects of life were controlled by the state. The Germanic peoples—also referred to as the Nordic race—were considered by the Nazis to be the purest representation of Aryanism, and therefore the master race. Concentration camps, established as early as 1933, were used to hold political prisoners and opponents of the regime. The number of camps quadrupled between 1939 and 1942 to 300+, as slave-laborers from across Europe, Jews, political prisoners, criminals, homosexuals, gypsies, the mentally ill and others were imprisoned. The system which began as an instrument of political oppression culminated in the mass genocide of Jews and others deemed undesirable in the Holocaust. The nazis persecuted and murdered homosexuals, members of the catholic church and Polish. Nazis also practiced eugenics and engaged in acts described as war crimes.
Germany made increasingly aggressive demands, threatening war if they were not met. Britain and France responded with appeasement, hoping Hitler would finally be satisfied. Hitler invaded Poland in September 1939, starting World War II in Europe. In alliance with Benito Mussolini's Italy, Germany conquered France and most of Europe by 1940, and threatened its remaining major foe: Great Britain. People in occupied territories were subjected to forced labour. After the german invasion of the Soviet Union in June 1941, the tide turned against the Third Reich with the major military defeats of the Battle of Stalingrad and the Battle of Kursk in 1943. The Soviet counter-attacks became the largest land battles in history. Nazi Germany engaged in a policy of deliberate maltreatment of Soviet prisoners of war. Germany was overrun in 1945 by the Soviets from the east and the Allies from the west. After the surrender of Nazi Germany, the victorious Allies initiated a policy of denazification and put the Nazi leadership on trial for war crimes at the Nuremberg Trials.
Neo-Nazism borrows elements from Nazi doctrine, including ultranationalism, racism, ableism, xenophobia, homophobia, antiziganism, antisemitism, and initiating the Fourth Reich. Holocaust denial is a common feature, as is the incorporation of Nazi symbols and admiration of Adolf Hitler. Neo-Nazi activity is a global phenomenon, with organized representation in many countries, as well as international networks. In some European and Latin American countries, laws have been enacted that prohibit the expression of pro-Nazi, racist, anti-Semitic or homophobic views. Many Nazi-related symbols are banned in European countries in an effort to curtail neo-Nazism.