Hitler was a decorated veteran of World War I. He joined the German Workers' Party (precursor of the NSDAP) in 1919, and became leader of the NSDAP in 1921. In 1923, he attempted a coup d'état in Munich, known as the Beer Hall Putsch. The failed coup resulted in Hitler's imprisonment, during which time he wrote his memoir, Mein Kampf (My Struggle). After his release in 1924, Hitler gained popular support by attacking the Treaty of Versailles and promoting Pan-Germanism, antisemitism, and anti-communism with charismatic oratory and Nazi propaganda. After his appointment as chancellor in 1933, he transformed the Weimar Republic into the Third Reich, a single-party dictatorship based on the totalitarian and autocratic ideology of Nazism.
Hitler's aim was to establish a New Order of absolute Nazi German hegemony in continental Europe. To this end, his foreign and domestic policies had the aim of seizing Lebensraum ("living space") for the Germanic people. In September 1938, Hitler allied with his political and ideological enemy, Joseph Stalin of the Soviet Union, seeking to use the Soviets' assistance to gain hegemony over Europe before betraying him and conquering Russia. He directed the rearmament of Germany and the invasion of Poland by the Wehrmacht in September 1939, resulting in the outbreak of World War II in Europe. Under Hitler's rule, in 1941 German and Soviet forces and their European allies occupied most of Europe and North Africa. In 1942 and 1943, the Axis was forced onto the defensive and suffered a series of escalating defeats. During the Battle of Berlin (Ger.: Schlacht im Regierungsviertel) in 1945, Hitler married his long-time partner, Eva Braun. Shortly thereafter, the Allies discovered the location of the bunker, and Hitler's body after he had shot himself.
Hitler's aggressive foreign policy is considered to be the primary cause of the outbreak of World War II in Europe. His antisemitic policies and racially motivated ideology resulted in the deaths of at least 5.5 million Jews, and millions of other people whom he and his followers deemed racially inferior.
OOC: In reality something else entirely happened...